Curable resin film and first protective film forming sheet

ABSTRACT

A curable resin film of the present invention forms a first protective film ( 1   a ) by attaching the curable resin film containing an epoxy-based thermosetting component having a weight-average molecular weight of 200 to 4,000 to a surface ( 5   a ) of a semiconductor wafer ( 5 ) having a plurality of bumps ( 51 ) with an average peak height (h1) of 50 to 400 μm, an average diameter of 60 to 500 μm, and an average pitch of 100 to 800 μm, heating the attached curable resin film at 100° C. to 200° C. for 0.5 to 3 hours, and curing the heated curable resin film, and when longitudinal sections thereof are observed by a scanning electron microscope, a ratio (h3/h1) of an average thickness (h3) of the first protective film ( 1   a ) at a center position between the bumps ( 51 ) to an average peak height (h1) of the bumps ( 51 ), and a ratio (h2/h1) of an average thickness (h2) of the first protective film ( 1   a ) at a position being in contact with the plurality of bumps ( 51 ) to the average peak height (h1) satisfy a relationship represented by the following expression of [{(h2/h1)−(h3/h1)}≤0.1].

TECHNICAL FIELD

The present invention relates to a curable resin film and a firstprotective film forming sheet provided with the curable resin film.

Priority is claimed on Japanese Patent Application No. 2015-217111,filed on Nov. 4, 2015, the content of which is incorporated herein byreference.

BACKGROUND ART

In the related art, in a case in which a multi-pin LSI package, which isused in MPU or a gate array, is mounted on a printed wiring board, aflip chip mounting method in which a semiconductor chip in which convexelectrodes (bumps) made of eutectic solder, high-temperature solder,metal, or the like are formed in connection pad portions is used, andthese bumps are made to face, brought into contact with, andmelting/diffusion-joined to the corresponding terminal portions on achip mounting substrate using a so-called face down method has beenemployed.

The semiconductor chip that is used in this mounting method is obtainedby, for example, dividing a semiconductor wafer having bumps formed on acircuit surface by grinding a surface opposite to the circuit surface ordicing the semiconductor wafer. In the process of obtaining theabove-described semiconductor chip, generally, for the purpose ofprotecting a circuit surface and a bump of the semiconductor wafer, acurable resin film is attached to a bump-formed surface, and this filmis cured so as to form a protective film on the bump-formed surface. Assuch a curable resin film, those containing a thermosetting componentthat is cured by heating are widely used. As a protective film formingsheet including the above-described curable resin film, a protectivefilm forming sheet formed by stacking a thermoplastic resin layer havinga predetermined thermal elastic modulus on the film and further stackinga thermoplastic resin layer which is not plastic at 25° C. on theuppermost layer of the thermoplastic resin layer has been disclosed (forexample, refer to Patent Document 1). According to Patent Document 1,this protective film forming sheet is excellent in terms of the bumpfilling property of the protective film, the wafer workability, theelectric connection reliability after resin sealing, and the like.

CITATION LIST Patent Literature

[Patent Document 1] Japanese Unexamined Patent Application, FirstPublication No. 2005-028734

SUMMARY OF INVENTION Technical Problem

On the other hand, when manufacturing a semiconductor chip by using aprotective film forming sheet provided with a curable resin film asdescribed above, after a protective film is formed on a bump-formedsurface of a semiconductor wafer by thermally curing the curable resinfilm, this protective film is greatly distorted in a concave shape atthe position between the bumps in some cases (refer to FIG. 6). In FIG.6, a protective film 101 a formed on a surface 105 a, which is asurface, on which a bump 151 is formed on a semiconductor wafer 105, bythermally curing a thermosetting resin film is greatly distortedconcavely on a side of the surface 105 a. Such a large distortion in aconcave shape of the protective film 101 a is considered to occur due tocontraction or the like when the curable resin film is cured on thesurface 105 a of the semiconductor wafer 105.

In this way, if the large distortion in the concave shape occurs on theprotective film 101 a on the semiconductor wafer 105, for example, whenperforming inspection of the circuit surface in a manufacturing step ofthe semiconductor wafer, there is a possibility that deviation occurs inalignment between an inspection apparatus and the semiconductor wafer,so that it is difficult to perform accurate inspection. In addition,when the large distortion in the concave shape occurs on the protectivefilm 101 a, at the time of dicing the semiconductor wafer 105 in chipunits using a dicing apparatus, there is a possibility that deviationoccurs in alignment between a dicing saw provided in the dicingapparatus and the semiconductor wafer, so that it is difficult toperform accurate dicing. As a cause of the deviation of the alignment asdescribed above, it is considered that the protective film 101 a islargely distorted in the concave shape, and thus a lens action occurs inthis concave portion, and the shape of the surface 105 a which is acircuit surface of the semiconductor wafer 105, for example, the shapeof a pattern 152 or the position thereof cannot be accurately detected.

Therefore, in the related art, in a case where the large distortion inthe concave shape occurs on the protective film 101 a on thesemiconductor wafer 105, yield of the semiconductor chip is lowered orthe reliability as a semiconductor package is deteriorated, which is aserious problem.

The present invention has been made in view of the above problems, andan object of the present invention is to provide a curable resin filmand a first protective film forming sheet, which are capable ofsuppressing occurrence of large distortion in a concave shape on a firstprotective film when the first protective film is formed on abump-formed surface of the semiconductor wafer.

Solution to Problem

In order to solve the above-mentioned problems, the inventors of thepresent invention have extensively studied experiments and studies. As aresult, it has been found that after optimizing the weight-averagemolecular weight of the curable component contained in the curable resinfilm used for forming the first protective film, when a dimensionalrelationship between of the first protective film cured underpredetermined conditions and the bump is appropriately defined, on asemiconductor wafer having a plurality of bumps of a predetermineddimensional shape and arrangement condition, the occurrence of the largedistortion in the concave shape on the first protective film disposedbetween the bumps can be suppressed, and thereby the present inventionhas been completed.

That is, according to the present invention, there is provided a curableresin film for forming the first protective film on a surface having aplurality of bumps on the semiconductor wafer by being attached to thesurface and being cured, in which the curable resin film contains anepoxy-based thermosetting component having a weight-average molecularweight of 200 to 4,000 as a curable component, a first protective filmthat protects the plurality of bumps is formed by attaching the curableresin film to a surface of the semiconductor wafer having the pluralityof bumps with an average peak height h1 of 50 to 400 μm, an averagediameter D of 60 to 500 μm in a plan view, and an average pitch P of 100to 800 μm, heating the attached curable resin film at 100° C. to 200° C.for 0.5 to three hours, and curing the heated curable resin film, andwhen longitudinal sections of the first protective film and thesemiconductor wafer having the plurality of bumps are observed by ascanning electron microscope, a ratio (h3/h1) of an average thickness h3of the first protective film at a center position between the pluralityof bumps to the average peak height h1 of the plurality of bumps, and aratio (h2/h1) of an average thickness h2 of the first protective film ata position being in contact with the plurality of bumps to the averagepeak height h1 satisfy a relationship represented by the followingExpression (1).

{(h2/h1)−(h3/h1)}≤0.1  (1)

In addition, according to the present invention, there is provided acurable resin film for forming the first protective film on a surfacehaving a plurality of bumps on the semiconductor wafer by being attachedto the surface and being cured, in which the curable resin film containsan energy ray-curable component having a weight-average molecular weightof 200 to 4,000 as a curable component, a first protective film thatprotects the plurality of bumps is formed by attaching the curable resinfilm to a surface of the semiconductor wafer having the plurality ofbumps with an average peak height h1 of 50 to 400 μm, an averagediameter D of 60 to 500 μm in a plan view, and an average pitch P of 100to 800 μm, irradiating the attached curable resin film with energy raysunder a condition of illuminance of 50 to 500 mW/cm², and lightintensity of 100 to 2,000 mJ/cm², and curing the irradiated curableresin film, and when longitudinal sections of the first protective filmand the semiconductor wafer having the plurality of bumps are observedby a scanning electron microscope, a ratio (h3/h1) of an averagethickness h3 of the first protective film at a center position betweenthe plurality of bumps to the average peak height h1 of the plurality ofbumps, and a ratio (h2/h1) of an average thickness h2 of the firstprotective film at a position being in contact with the plurality ofbumps to the average peak height h1 satisfy a relationship representedby the following Expression (1).

{(h2/h1)−(h3/h1)}≤0.1  (1)

In the above configuration, it is more preferable that the curable resinfilm of the present invention contains 5% to 80% by mass of fillerhaving an average particle diameter of 5 to 1,000 nm.

In addition, according to the present invention, there is provided afirst protective film forming sheet including the curable resin filmhaving any configuration described above on one surface of a firstsupporting sheet.

Advantageous Effects of Invention

According to the present invention, the curable resin film and the firstprotective film forming sheet provided with the curable resin film,after optimizing the weight-average molecular weight of the curablecomponent contained in the curable resin film used for forming the firstprotective film, when a dimensional relationship between of the firstprotective film cured under predetermined conditions and the bump isappropriately defined, on a semiconductor wafer having a plurality ofbumps of a predetermined dimensional shape and arrangement condition.With this, it is possible to suppress the occurrence of the largedistortion in the concave shape the first protective film disposedbetween the bumps. As a result, for example, the inspection in a step ofmanufacturing a semiconductor wafer and the alignment accuracy in a stepof dicing the semiconductor wafer into a chip improve. Therefore, theinspection accuracy and the dicing accuracy in the manufacturing stepimprove, and a semiconductor package excellent in the reliability can bemanufactured.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a sectional view schematically showing an example ofprocedure of forming a first protective film on a bump-formed surface ofa semiconductor wafer by using a curable resin film according to thepresent invention, and is a diagram showing a state in which the curableresin film is attached to the bump-formed surface of the semiconductorwafer.

FIG. 1B is a sectional view schematically showing an example ofprocedure of forming a first protective film on the bump-formed surfaceof the semiconductor wafer by using the curable resin film according tothe present invention, and is a diagram showing a state in which thefirst protective film is formed by thermally curing the curable resinfilm.

FIG. 2 is a plan view schematically showing an example of a state inwhich the first protective film is formed on the bump-formed surface ofthe semiconductor wafer by using the curable resin film according to thepresent invention.

FIG. 3 is a sectional view schematically showing an example of a layerstructure of the curable resin film and the first protective filmforming sheet according to the present invention.

FIG. 4 is a sectional view schematically showing another example of alayer structure of the curable resin film and the first protective filmforming sheet according to the present invention.

FIG. 5 is a sectional view schematically showing still another exampleof a layer structure of the curable resin film and the first protectivefilm forming sheet according to the present invention.

FIG. 6 is a diagram showing a state in which the protective film isformed on the bump-formed surface of the semiconductor wafer by usingthe curable resin film in the related art.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of a curable resin film of the presentinvention and a first protective film forming sheet using the same willbe described in detail with reference to the drawings of FIGS. 1 to 5 ofthe present invention and the drawing of FIG. 6 of the related art, asnecessary. FIGS. 1A and 1B are sectional views schematically showing anexample of procedure of forming the first protective film on thebump-formed surface of the semiconductor wafer by using the curableresin film according to the present invention, and FIG. 2 is a plan viewof the semiconductor wafer shown in FIG. 1B. In addition, FIGS. 3 to 5are sectional views schematically showing each example of the layerstructure of the curable resin film and the first protective filmforming sheet. Further, FIG. 6 is a diagram showing an example in whichthe first protective film is formed on the bump-formed surface of thesemiconductor wafer by using the curable resin film in the related art.Note that, in the drawings used in the following description, for thesake of easy understanding of the features of the present invention, andfor the sake of convenience, a portion serving as a main part issometimes enlarged and the dimensional ratio and the like of eachcomponent may be different from the actual one. Further, in the presentspecification, the above-described “film” may be referred to as “layer”in some cases.

The curable resin film 1 according to the present invention as shown inFIGS. 3 to 5 are for forming a first protective film 1 a that protects aplurality of bumps 51 on a semiconductor wafer 5 as shown in FIGS. 1Aand 1B, and FIG. 2. That is, the curable resin film 1 of the presentinvention is used to form a first protective film 1 a on the surface 5 aby being attached to the surface 5 a having the plurality of bumps 51 onthe semiconductor wafer 5 as shown in FIG. 1A, and being cured as shownin FIG. 1B.

In addition, a first protective film forming sheet 1A according to thepresent invention is provided with the curable resin film 1 on onesurface 11 a of the first supporting sheet 11, as shown in FIG. 3. Thatis, before attaching the curable resin film 1 on the semiconductor wafer5, the first protective film forming sheet 1A transports the curableresin film 1 as a product package, for example, or stably supports andprotects the curable resin film 1 by the first supporting sheet 11 whentransporting the curable resin film 1 in the process.

Hereinafter, configurations of the curable resin film 1 of the presentinvention and the first protective film forming sheet 1A arespecifically described in order.

<<Curable Resin Film>>

As described above, the curable resin film of the present invention is alayer (film) for protecting the plurality of bumps 51 on the surface 5 aof the semiconductor wafer 5, and the first protective film 1 a isformed by heating or curing with energy ray irradiation.

<Curable Resin Film Containing Thermosetting Component>

The curable resin film 1 of the present invention is configured tocontain an epoxy-based thermosetting component having a weight-averagemolecular weight of 200 to 4,000 as a curable component.

In addition, the curable resin film 1 of the present invention is usedto form the first protective film by being attached to the semiconductorwafer 5 having the plurality of bumps 51 on the surface 5 a as shown inFIGS. 1A and 1B.

The curable resin film 1 of the present invention forms the firstprotective film 1 a that protects the plurality of bumps 51 and thesurface 5 a by attaching the curable resin film onto the semiconductorwafer 5 having the plurality of bumps 51 with an average peak height h1of 50 to 400 μm, an average diameter D of 60 to 500 μm in a plan view,and an average pitch P of 100 to 800 μm, and heating the attachedcurable resin film at 100° C. to 200° C. for 0.5 to 3 hours, and curingthe heated curable resin film, and when longitudinal sections of thefirst protective film 1 a and the semiconductor wafer 5 are observed bya scanning electron microscope, a ratio (h3/h1) of an average thicknessh3 of the first protective film 1 a at a center position between theplurality of bumps 51 to an average peak height h1 of the plurality ofbumps 51, and a ratio (h2/h1) of an average thickness h2 of the firstprotective film 1 a at a position being in contact with the plurality ofbumps 51 to the average peak height h1 satisfy a relationshiprepresented by the following Expression (1).

{(h2/h1)−(h3/h1)}≤0.1  (1)

The “average thickness h3 of the first protective film 1 a at a centerposition between the plurality of bumps 51” defined in the presentinvention substantially means a portion in which the thickness of thefirst protective film 1 a in the vicinity of the center between theplurality of bumps 51 is substantially the thinnest.

Also, the “average pitch P” in “the plurality of bumps 51 having theplurality of bumps 51 with average pitch P of 100 to 800 μm” defined inthe present invention means the average pitch between the center linesof each bump 51. Note that, the average peak height h1 of the pluralityof bumps, average thickness h2 of the first protective film at theposition being in contact with the plurality of bumps, the averagethickness h3 of the first protective film at the center position betweenthe plurality of bumps, the average pitch P, and the average diameter Dcan be measured by image analysis using a scanning electron microscope.

As described above, the curable resin film 1 of the present invention isused by being attached to the surface 5 a having the bump 51 in thesemiconductor wafer 5. Then, the curable resin film 1 after attachmenthas an increase in fluidity by heating, spreads between the plurality ofbumps 51 so as to cover the bumps 51, is close contact with the surface(circuit surface) 5 a, and embeds the bump 51 while covering the surface51 a of the bump 51, particularly, the vicinity of the surface 5 a ofthe semiconductor wafer 5. The curable resin film 1 in such a state isthermally cured by being further heated so as to finally form the firstprotective film 1 a and protects the bump 51 in a state of being inclose contact with the surface Ma on the surface 5 a. The semiconductorwafer 5 to which the curable resin film 1 is attached is detached andremoved from a first supporting sheet (refer to the first supportingsheet 11 provided in the first protective film forming sheet 1A as shownin FIG. 3) after grinding the surface (the back surface 5 b) on the sideopposite to the surface 5 a which is the circuit surface. Subsequently,embedding of the bumps 51 and formation of the first protective film 1 aare performed by heating the curable resin film 1, and finally, thesemiconductor wafer is incorporated into a semiconductor device (notshown) in a state where this first protective film 1 a is provided.

The plurality of the bumps 51 are provided on surface 5 a which is thecircuit surface of the semiconductor wafer 5. The bump 51 has, forexample, a shape of a sphere a part of which is cut out along a flatsurface, and a flat surface corresponding to a portion exposed bycutting out the above-described part is in contact with the surface 5 aof the semiconductor wafer 5.

The first protective film 1 a is formed with the curable resin film 1 ofthe present invention, covers the surface 5 a of the semiconductor wafer5, and further covers the top surface and the surface 51 a other thanthe vicinity thereof among the bump 51. In this way, the firstprotective film 1 a is close contact with the top surface of the bumps51 and the area other than the vicinity thereof among the surfaces 51 aof the bumps 51, and is also close contact with the surface (circuitsurface) 5 a the semiconductor wafer 5 so as to embed the bump 51. Inthe examples as shown in FIGS. 1A and 1B, the bumps have substantiallyspherical shapes (shapes in which a part of the spheres are cut out byplanes) as described above, but the shape of the bump that can beprotected by the first protective film 1 a formed from the curable resinfilm 1 according to the present invention is not limited thereto.Examples of preferred bumps include a bump having a shape obtained bystretching the bump having a substantially spherical shape as shown inFIGS. 1A and 1B, in a height direction (direction orthogonal to thesurface 5 a of the semiconductor wafer 5 in FIGS. 1A and 1B), that is, ashape of a spheroid which is substantially long spherical (a shape inwhich a portion including one end in the major axis direction of aspheroid which is long spherical is cut out by a plane), and a bumphaving a shape obtained by crushing the bump having a substantiallyspherical shape in a height direction, that is, a shape of a spheroidwhich is substantially oblate (a shape in which a portion including oneend in the minor axis direction of a spheroid which is substantiallyoblate is cut out by a plane). The first protective film 1 a formed bythe curable resin film 1 according to the present invention can beapplied to the bumps having any other shapes, and particularly, in acase where the shape of the bump is a spherical shape including aspherical shape or an elliptical shape as described above, the effect ofprotecting the surface of the semiconductor wafer and the bump isremarkably obtained.

In addition, as described above, the curable resin film 1 of the presentinvention employs a configuration in which after optimizing theweight-average molecular weight of the curable component contained inthe curable resin film 1, when a dimensional relationship between of thefirst protective film 1 a cured under predetermined conditions and theplurality of bumps 51 are appropriately defined, on the semiconductorwafer 5 having the plurality of bumps 51 of a predetermined dimensionalshape and arrangement condition. With this, it is possible to suppressthe occurrence of the large distortion in the concave shape the firstprotective film 1 a formed and disposed between the plurality of bumps51. With this, for example, it is possible to obtain an effect ofimproving the inspection in a step of manufacturing a semiconductorwafer and the alignment accuracy in a step of dicing the semiconductorwafer into a chip.

More specifically, regarding the curable resin film 1, as shown in FIG.1B, in the first protective film 1 a cured under the predeterminedheating conditions, the ratio (h3/h1) of the average thickness h3 of thefirst protective film 1 a at the center position A between the pluralityof bumps 51 to the average peak height h1 of the plurality of bumps 51,and the ratio (h2/h1) of the average thickness h2 of the firstprotective film 1 a at the position B being in contact with theplurality of bumps 51 satisfy the relationship represented by thefollowing expression {{(h2/h1)−(h3/h1)}≤0.1}. That is, in the firstprotective film 1 a formed by thermally curing the curable resin film 1,as represented by the above expression, the average thickness h2 at theposition B being in contact with the plurality of bumps 51 and theaverage thickness h3 at the center position A between the plurality ofbumps 51 are defined in a relationship in which the average thickness h2is thicker and the difference between both is minimized. That is,according to one aspect of the present invention, examples thereofinclude a curable resin film and a first protective film forming sheetwhich have the properties satisfying the above relationship.

In addition, as shown in FIGS. 1A and 1B, and FIG. 2, the firstprotective film 1 a formed of the curable resin film 1 according to thepresent invention is prevented from shrinking in the film during curing,and thus it is possible to effectively suppress the occurrence of thelarge distortion in a concave shape. For example, in FIG. 1B and FIG. 2,the large distortion does not occur in the first protective film 1 a andfluoroscopic defects due to a lens effect or the like do not occur, sothat a circuit pattern 52 on the surface 5 of the semiconductor wafer 5can be clearly recognized. With this, it is possible to accuratelydetect the arrangement shape and the like of the circuit pattern 52 onthe surface 5 a of the semiconductor wafer 5, and therefore, forexample, various inspections in the manufacturing step of thesemiconductor wafer 5, and the alignment accuracy between the inspectionapparatus, the manufacturing apparatus, the semiconductor wafer 5 in astep of dicing the semiconductor wafer 5 in a chip shape improve.Therefore, the inspection accuracy and the dicing accuracy improve, anda semiconductor package excellent in the reliability can bemanufactured.

In the present invention, the curable component contained in the curableresin film 1 is configured to contain an epoxy-based thermosettingcomponent having a weight-average molecular weight of 200 to 4,000. Whenthe curable resin film 1 contains the epoxy-based thermosettingcomponent within the above range, it is possible to minimize theoccurrence of deformation due to thermal shrinkage or the like in thefirst protective film 1 a after thermally curing. With this, it ispossible to suppress the occurrence of the large distortion in theconcave shape on the thermally-cured first protective film 1 a.Meanwhile, in the present embodiment, unless particularly otherwisedescribed, the weight-average molecular weight refers to apolystyrene-equivalent value measured using gel permeationchromatography (GPC).

Further, in the present invention, from the viewpoint of more remarkablyobtaining the above action and effect, the weight-average molecularweight of the epoxy-based thermosetting component contained in thecurable resin film 1 is more preferably 250 to 3,500, and particularlypreferably 300 to 3,000.

Detailed components of the epoxy-based thermosetting component will bedescribed later.

In the present invention, the curable resin film 1 may further contain afiller (D) which will be described in detail later. In this case, theaverage particle diameter and the amount of the filler (D) are notparticularly limited, and for example, the filler having the averageparticle diameter of 5 to 1,000 nm is preferably contained in thecurable resin film 1 by 5% to 80% by mass of the entire mass of thethermosetting resin composition forming the curable resin film 1. Whenthe average particle diameter and the amount of the filler (D) containedin the curable resin film 1 are limited to the above-mentioned range, itis possible to obtain an effect in which the occurrence of the largedistortion in a concave shape in the cured first protective film 1 a asdescribed above can be more remarkably suppressed. It is considered thatthe reason for this is that when a certain percentage of the filler (D)contained in the curable resin film 1 is limited to those having anaverage particle diameter in a predetermined range, shrinkage or thelike which is likely to occur at the time of curing the curable resinfilm 1 can be effectively suppressed.

Note that, the average particle diameter of the filler (D) is morepreferably 5 to 500 nm, and particularly preferably 10 to 300 nm, fromthe viewpoint that the above action and effect can be more remarkablyobtained. Here, the above average particle diameter is obtained bymeasuring the outer diameter of one particle at several places andcalculating the average value thereof.

In addition, the amount of the filler (D) in the curable resin film 1 ismore preferably 7% to 60% by mass of the entire mass of thethermosetting resin composition forming the curable resin film 1 afterlimiting the average particle diameter to the above range.

Detailed components of the filler (D) will be described later.

The thickness of the first protective film 1 a after curing is notparticularly limited, and the entire average thickness may be set withinthe range of the dimensional relationship represented by the aboveExpression (1). On the other hand, when considering of the protectionfunction of the surface 5 a and the bump 51 of the semiconductor wafer5, the average thickness h3 of the first protective film 1 a at thecenter position A between the plurality of bumps 51 is preferably set tobe about 10 to 400 μm, and the average thickness h2 of the firstprotective film 1 a at the position B being in contact with the bump 51is preferably set to be about 1 to 350 μm.

Here, FIG. 6 schematically shows a cross section in a state where theprotective film 101 a is formed on the surface 105 a which is thebump-formed surface of the semiconductor wafer 105 through the method byusing the conventional curable resin film. As shown in FIG. 6, in a caseof forming the protective film 101 a using the conventional curableresin film in which a dimensional relationship between theweight-average molecular weight of the curable component contained inthe curable resin film, the protective film 101 a cured under thepredetermined conditions, and the bump 151 is not appropriately set,protective film 101 a has a large distortion in a concave shape at aposition between the bumps 151 due to the shrinkage or the likeoccurring at the time of curing the curable resin film.

As shown in FIG. 6, in a case where the large distortion in a concaveshape occurs on the protective film 101 a on the semiconductor wafer105, a lens action occurs in the concave portion, and thereby it isdifficult to accurately detect the shape on the surface 105 a which isthe circuit surface of the semiconductor wafer 105 in some cases. Forthis reason, for example, when performing inspection of the circuitsurface in a manufacturing step of the semiconductor wafer, there is apossibility that deviation occurs in alignment between an inspectionapparatus and the semiconductor wafer, so that it is difficult toperform accurate inspection. In addition, in the case where the largedistortion in the concave shape occurs on the protective film 101 a, atthe time of dicing the semiconductor wafer 105 in chip units, there is apossibility that deviation occurs in alignment between a dicing sawprovided in the dicing apparatus and the semiconductor wafer, so that itis difficult to perform accurate dicing. Therefore, in a case where theprotective film 101 a is formed on the semiconductor wafer 105 by usinga method of using the conventional curable resin film, yield of thesemiconductor chip to be obtained is lowered or the reliability as asemiconductor package is deteriorated, which is a serious problem.

In contrast, according to the curable resin film 1 of the presentinvention, as described above, the weight-average molecular weight ofthe curable component contained in the curable resin film used forforming the first protective film 1, and a dimensional relationshipbetween the first protective film 1 a cured under predeterminedconditions and the plurality of bumps 51 on the semiconductor wafer 5having the plurality of bumps 51 of a predetermined dimensional shapeand arrangement condition are appropriately defined. With this, it ispossible to suppress the occurrence of the large distortion in theconcave shape the first protective film 1 a disposed between the bumps51. Accordingly, the alignment accuracy in the step of performing theinspection step and the dicing step of the manufacturing step improves,and thus the inspection accuracy and the dicing accuracy improve,thereby manufacturing a semiconductor package excellent in thereliability.

<Curable Resin Film Containing Energy Ray-Curable Component>

The curable component contained in the curable resin film 10 of thepresent invention is configured to contain an energy ray-curablecomponent having a weight-average molecular weight of 200 to 4,000, withrespect to the curable resin film 1 containing the thermosettingcomponent as described above.

Similar to the curable resin film 1 containing the above-describedthermosetting component, the curable resin film 10 of the presentinvention is used to form the first protective film by being attached tothe semiconductor wafer 5 having the plurality of bumps 51 on thesurface 5 a as shown in FIGS. 1A and 1B.

The curable resin film 10 of the present invention forms the firstprotective film 1 a that protects the plurality of bumps 51 and thesurface 5 a by attaching the curable resin film onto the semiconductorwafer 5 having the plurality of bumps 51 with an average peak height h1of 50 to 400 μm, an average diameter D of 60 to 500 μm in a plan view,and an average pitch P of 100 to 800 μm, and irradiating the attachedcurable resin film with energy rays under conditions of illuminance of50 to 500 mW/cm², and light intensity of 100 to 2,000 mJ/cm² and curingthe irradiated curable resin film, and when longitudinal sections of thefirst protective film 1 a and the semiconductor wafer 5 are observed bya scanning electron microscope, a ratio (h3/h1) of an average thicknessh3 of the first protective film 1 a at a center position between theplurality of bumps 51 to an average peak height h1 of the plurality ofbumps 51, and a ratio (h2/h1) of an average thickness h2 of the firstprotective film 1 a at a position being in contact with the plurality ofbumps 51 to the average peak height h1 satisfy a relationshiprepresented by the following Expression (1).

{(h2/h1)−(h3/h1)}≤0.1  (1)

That is, the curable resin film 10 of the present invention is common tothe above-described curable resin film 1 from the viewpoint of adimensional shape and an arrangement condition of the plurality of bumps51 on the semiconductor wafer 5, and each condition of a dimensionalrelationship between the cured first protective film 1 a and theplurality of bumps 51. On the other hand, the curable resin film 10 ofthe present invention is different from the above-described curableresin film 1 from the viewpoint that the curable resin film 10 containsan energy ray-curable component as a curable component, and is cured bybeing irradiated with energy rays under curing conditions with theilluminance of 50 to 500 mW/cm², and the light intensity of 100 to 2000mJ/cm².

In the present invention, the curable component contained in the curableresin film 10 is configured to contain an energy ray-curable componenthaving a weight-average molecular weight of 200 to 4,000. When thecurable resin film 10 contains the energy ray-curable component withinthe above range, it is possible to minimize the occurrence ofdeformation due to thermal shrinkage or the like in the first protectivefilm 1 a after curing by energy ray irradiation. With this, it ispossible to suppress the occurrence of the large distortion in theconcave shape on the cured first protective film 1 a.

Note that, in the present invention, “energy rays” refer to rays havingenergy quanta in electromagnetic waves or charged particle radiation,and examples thereof include ultraviolet rays, electron beams, and thelike.

Ultraviolet rays can be radiated using, for example, a high-pressuremercury lamp, a fusion lamp, a xenon lamp, LED, or the like as anultraviolet ray source. As the electron beams, electron beams generatedusing an electron beam accelerator or the like can be radiated.

In the present invention, “being energy ray-curable” refers to aproperty of being cured by being irradiated with energy rays, and “beingnon-energy ray-curable” refers to a property of not being cured by beingirradiated with energy rays.

Further, in the present invention, from the viewpoint of more remarkablyobtaining the above action and effect, the weight-average molecularweight of the energy ray-curable component contained in the curableresin film 10 is more preferably 200 to 4,000, and particularlypreferably 300 to 4,000.

Detailed components of the energy ray-curable component will bedescribed later.

<<First Protective Film Forming Sheet (Curable Resin Film)>>

Hereinafter, the configurations of curable resin films 1 and 10 havingthe above-described configuration, and the first protective film formingsheet 1A in which any one of the above curable resin films is providedon the first supporting sheet are further described in detail.

<First Supporting Sheet>

The first supporting sheet 11 provided with first protective filmforming sheet 1A may be a sheet made of a single layer (monolayer) or asheet made of a plurality of layers of two or more layers. In a case inwhich the first supporting sheet 11 is made of a plurality of layers,the constituent materials and the thicknesses of the plurality of layersmay be identical to or different from one another, and the combinationof the plurality of layers is not particularly limited as long as theeffects of the present invention are not impaired.

Meanwhile, in the present embodiment, the sentence “component materialsof a plurality of layers and the thickness may be identical to ordifferent from one another” means that “all of the layers may beidentical to one another, all of the layers may be different from oneanother, or only some of the layers may be identical to one another”,which will be true not only for the first supporting sheet but also forother elements. Furthermore, the sentence “a plurality of layers isdifferent from one another” means that “at least one of the constituentmaterials and the thicknesses of the respective layers are differentfrom one another”.

Examples of a preferred the first supporting sheet 11 include astructure formed by stacking a first pressure-sensitive adhesive layeron a first base material, a structure formed by stacking a firstinterlayer on the first base material and stacking the firstpressure-sensitive adhesive layer on the first interlayer, and astructure formed of the first base material.

An example of the first protective film forming sheet according to thepresent invention will be described with reference to FIGS. 3 to 5 foreach kind of such first supporting sheet.

FIG. 3 is a sectional view schematically showing an example of the firstprotective film forming sheet of the present invention. In the firstprotective film forming sheet 1A as shown in FIG. 3, the firstsupporting sheet 11 is formed by stacking the first pressure-sensitiveadhesive layer 13 on the first base material 12. That is, the firstprotective film forming sheet 1A is configured to include the firstpressure-sensitive adhesive layer 13 on the first base material 12, andthe curable resin film 1 including the thermosetting component on thefirst pressure-sensitive adhesive layer 13. The first supporting sheet11 is a stacked body of the first base material 12 and the firstpressure-sensitive adhesive layer 13, in which the curable resin film 1is provided on one surface 11 a of the first supporting sheet 11, thatis, on one surface 13 a of the first pressure-sensitive adhesive layer13.

In the first protective film forming sheet 1A, as described above, thecurable resin film 1 is used to be attached to the bump-formed surfaceof the semiconductor wafer, and is obtained by appropriately regulatinga dimensional relationship between of the first protective film 1 acured under predetermined conditions and the plurality of bumps 51, on asemiconductor wafer 5 having the plurality of bumps 51 of on thesemiconductor wafer 5 having the plurality of bumps 51 having theweight-average molecular weight, a predetermined dimensional shape andarrangement condition of the curable component to be e contained.

FIG. 4 is a sectional view schematically showing another example of thefirst protective film forming sheet of the present invention. Meanwhile,in FIG. 4, the same constituent element as in FIG. 3 is given the samereference sign as in FIG. 3 and will not be described in detail, and thesame is true for FIG. 5.

The first protective film forming sheet 1B as shown in FIG. 4 uses thefirst supporting sheet obtained by stacking the first interlayer on thefirst base material, and stacking the first pressure-sensitive adhesivelayer on the first interlayer. That is, the first protective filmforming sheet 1B is configured to include the first interlayer 14 on thefirst base material 12, the first pressure-sensitive adhesive layer 13on the first interlayer 14, and the curable resin film 1 on the firstpressure-sensitive adhesive layer 13. The first supporting sheet 11A isa stacked body obtained by stacking the first base material 12, thefirst interlayer 14, and the first pressure-sensitive adhesive layer 13in this order, in which the curable resin film 1 is provided on onesurface 11 a of the first supporting sheet 11A, that is, on one surface13 a of the first pressure-sensitive adhesive layer 13.

In other words, the first protective film forming sheet 1B is furtherprovided with the first interlayer 14 between the first base material 12and the first pressure-sensitive adhesive layer 13 in the firstprotective film forming sheet 1A as shown in FIG. 3.

In the first protective film forming sheet 1B, as described above, thecurable resin film 1 is used to be attached to the bump-formed surfaceof the semiconductor wafer, and is obtained by appropriately regulatinga dimensional relationship between of the first protective film 1 acured under predetermined conditions and the plurality of bumps 51, on asemiconductor wafer 5 having the plurality of bumps 51 of on thesemiconductor wafer 5 having the plurality of bumps 51 having theweight-average molecular weight, a predetermined dimensional shape andarrangement condition of the curable component to be e contained.

FIG. 5 is a sectional view schematically showing still another exampleof the first protective film forming sheet of the present invention.

In the first protective film forming sheet 1C as shown in FIG. 5, thefirst supporting sheet is formed of only the first base material. Thatis, the first protective film forming sheet 1C is configured to includecurable resin film 1 on the first base material 12.

The first supporting sheet 11B is formed of only the first base material12, the curable resin film 1 is provided in direct contact with on onesurface 11 a of the first supporting sheet 11B, that is, one surface 12a of the first base material 12. In other words, the first protectivefilm forming sheet 1C is formed by removing the first pressure-sensitiveadhesive layer 13 in the first protective film forming sheet 1A as shownin FIG. 3.

In the first protective film forming sheet 1C, as described above, thecurable resin film 1 is used to be attached to the bump-formed surfaceof the semiconductor wafer, and is obtained by appropriately regulatinga dimensional relationship between of the first protective film 1 acured under predetermined conditions and the plurality of bumps 51, on asemiconductor wafer 5 having the plurality of bumps 51 of on thesemiconductor wafer 5 having the plurality of bumps 51 having theweight-average molecular weight, a predetermined dimensional shape andarrangement condition of the curable component to be e contained.

Hereinafter, each configuration of the first supporting sheet will bedescribed in detail.

[First Base Material]

The first base material provided with the first supporting sheet is asheet-form or film-form base material, and examples of a constituentmaterial thereof include the following various resins.

Examples of the resins forming the first base material includepolyethylene such as low-density polyethylene (LDPE), linear low-densitypolyethylene (LLDPE), and high-density polyethylene (HDPE); polyolefinother than polyethylene such as polypropylene, polybutene,polybutadiene, polymethylpentene, and norbornene resins; ethylene-basedcopolymers (copolymers obtained using ethylene as monomers) such asethylene-vinyl acetate copolymers, ethylene-(meth)acrylate copolymers,ethylene-(meth)acrylic acid ester copolymers, and ethylene-norbornenecopolymers; vinyl chloride-based resins (resins obtained using vinylchloride as monomers) such as polyvinyl chloride and vinyl chloridecopolymers; polystyrene; polycycloolefin; polyesters such aspolyethylene terephthalate, polyethylene naphthalate, polybutyleneterephthalate, polyethylene isophthalate, polyethylene-2,6-naphthalenedicarboxylate, and wholly aromatic polyesters in which all constituentunits have an aromatic cyclic group; copolymers of two or more polyesterdescribed above; poly(meth)acrylic acid esters; polyurethane;polyurethane acrylate; polyimide; polyamide; polycarbonate; fluororesin;polyacetal; modified polyphenylene oxides; polyphenylene sulfides;polysulfone; polyether ketones; and the like.

In addition, examples of the resins constituting the first base materialalso include polymer alloys such as mixtures of the polyester and otherresin are also exemplary examples. The polymer alloys of the polyesterand other resin are preferably polymer alloys in which the amount of theresin other than the polyester is relatively small.

In addition, examples of the resins constituting the first base materialalso include crosslinked resins in which one or more resins described asexemplary examples above are crosslinked with each other; modifiedresins such as ionomers for which one or more resins described asexemplary examples above are used; and the like.

Meanwhile, in the present embodiment, “(meth)acrylic acid” refers toboth “acrylic acid” and “methacrylic acid”. What has been describedabove is also true for terminologies similar to (meth)acrylic acid, forexample, “(meth)acrylate” refers to both “acrylate” and “methacrylate”,and “a (meth)acryloyl group” refers to both “an acryloyl group” and “amethacryloyl group”.

The forming the first base material may be constituted of only one typeor two or more types of the resins. In a case in which the first basematerial has two or more types of resins, the combination and ratiothereof can be arbitrarily selected.

The first base material may be a single layer (monolayer) or a pluralityof two or more layers. In a case in which the first base material is aplurality of layers, the respective layers in the plurality of layersmay be identical to or different from one another, and the combinationof the plurality of layers is not particularly limited.

The thickness of the first base material is preferably 5 to 1,000 μm,more preferably 10 to 500 μm, still more preferably 15 to 300 μm, andparticularly preferably 20 to 150 μm.

Here, “the thickness of the first base material” refers to the thicknessof the entire first base material, and, for example, the thickness ofthe first base material made up of a plurality of layers refers to thetotal thickness of all of the layers constituting the first basematerial.

The first base material is preferably a first base material having ahigh accuracy in thickness, that is, a first base material in which thevariation of the thickness is suppressed throughout the entire portion.Among the above-described constituent materials, examples of materialshaving a high accuracy in thickness that can be used to constitute theabove-described first base material include polyethylene, polyolefinother than polyethylene, polyethylene terephthalate, ethylene-vinylacetate copolymers, and the like.

The first base material may also contain, in addition to the mainconstituent material such as the resin, a variety of well-knownadditives such as a filler, a colorant, an antistatic agent, anantioxidant, an organic lubricant, a catalyst, and a softening agent(plasticizer).

The first base material may be transparent or opaque and may be coloreddepending on the purpose. In addition, other layers may be deposited onthe first base material.

In addition, in a case in which the first pressure-sensitive adhesivelayer described below or the curable resin layer is energy ray-curable,the first base material preferably transmits energy rays.

The first base material can be manufactured using a well-known method.For example, the first base material containing the resin can bemanufactured by forming a resin composition containing the resin.

[First Pressure-Sensitive Adhesive Layer]

The first pressure-sensitive adhesive layer has a sheet form or a filmform and contains a pressure-sensitive adhesive.

Examples of the pressure-sensitive adhesive include pressure-sensitiveadhesive resins such as acrylic resins (pressure-sensitive adhesivesmade of a resin having a (meth)acryloyl group), urethane-based resins(pressure-sensitive adhesives made of a resin having a urethane bond),rubber-based resins (pressure-sensitive adhesives made of a resin havinga rubber structure), silicone-based resins (pressure-sensitive adhesivesmade of a resin having a siloxane bond), epoxy-based resins(pressure-sensitive adhesives made of a resin having an epoxy group),polyvinyl ethers, and polycarbonate, and acrylic resins are preferred.

Meanwhile, in the present invention, “pressure-sensitive adhesiveresins” refer to both resins having a pressure-sensitive adhesivenessand resins having an adhesiveness, and examples thereof include not onlyresins having an adhesiveness for themselves but also resins exhibitinga pressure-sensitive adhesiveness when jointly used with othercomponents such as additives, resins exhibiting an adhesiveness due tothe presence of a trigger such as heat or water, and the like.

The first pressure-sensitive adhesive layer may be a single layer(monolayer) or a plurality of two or more layers. In a case in which thefirst pressure-sensitive adhesive layer is a plurality of layers, therespective layers in the plurality of layers may be identical to ordifferent from one another, and the combination of the plurality oflayers is not particularly limited.

The thickness of the first pressure-sensitive adhesive layer ispreferably 1 to 1,000 μm, more preferably 5 to 500 μm, and particularlypreferably 10 to 100 μm.

Here, “the thickness of the first pressure-sensitive adhesive layer”refers to the thickness of the entire first pressure-sensitive adhesivelayer, and, for example, the thickness of the first pressure-sensitiveadhesive layer made up of a plurality of layers refers to the totalthickness of all of the layers constituting the first pressure-sensitiveadhesive layer.

The first pressure-sensitive adhesive layer may be a firstpressure-sensitive adhesive layer formed using an energy ray-curablepressure-sensitive adhesive or a first pressure-sensitive adhesive layerformed using a non-energy ray-curable pressure-sensitive adhesive. Forthe first pressure-sensitive adhesive layer formed using an energyray-curable pressure-sensitive adhesive, it is possible to easily adjustthe properties before curing and after curing.

{{First Pressure-Sensitive Adhesive Composition}}

The first pressure-sensitive adhesive layer can be formed using a firstpressure-sensitive adhesive composition containing a pressure-sensitiveadhesive. For example, the first pressure-sensitive adhesive layer canbe formed at an intended portion by applying the firstpressure-sensitive adhesive composition to a target surface on which thefirst pressure-sensitive adhesive layer is to be formed and drying thefirst pressure-sensitive adhesive composition as necessary. A morespecific method for forming the first pressure-sensitive adhesive layerwill be described below in detail together with methods for formingother layers. The ratio between the amounts of components, which do notgasify at normal temperature, in the first pressure-sensitive adhesivecomposition is, generally, identical to the ratio between the amounts ofthe above-described components in the first pressure-sensitive adhesivelayer. Meanwhile, in the present embodiment, “normal temperature” refersto a temperature that is not particularly cooled or heated, that is, atemperature in an ordinary state, and examples thereof include atemperature of 15° C. to 25° C. and the like.

The first pressure-sensitive adhesive composition may be applied using awell-known method, and examples thereof include methods in which avariety of coaters such as an air knife coater, a blade coater, a barcoater, a gravure coater, a roll coater, a roll knife coater, a curtaincoater, a die coater, a knife coater, a screen coater, a Mayer barcoater, and a kiss coater are used.

The drying conditions of the first pressure-sensitive adhesivecomposition are not particularly limited; however, in a case in whichthe first pressure-sensitive adhesive composition contains a solventdescribed below, the first pressure-sensitive adhesive composition ispreferably heated and dried, and, in this case, the firstpressure-sensitive adhesive composition is preferably dried underconditions of, for example, 70° C. to 130° C. and 10 seconds to 5minutes.

In a case in which the first pressure-sensitive adhesive layer is energyray-curable, examples of the first pressure-sensitive adhesivecomposition containing an energy ray-curable pressure-sensitiveadhesive, that is, an energy ray-curable first pressure-sensitiveadhesive composition include a first pressure-sensitive adhesivecomposition (I-1) containing a non-energy ray-curable pressure-sensitiveadhesive resin (I-1a) (hereinafter, in some cases, abbreviated as “thepressure-sensitive adhesive resin (I-1a)”) and an energy ray-curablecompound; a first pressure-sensitive adhesive composition (I-2)containing an energy ray-curable pressure-sensitive adhesive resin(I-2a) in which an unsaturated group is introduced into a side chain ofthe non-energy ray-curable pressure-sensitive adhesive resin (I-1a)(hereinafter, in some cases, abbreviated as “the pressure-sensitiveadhesive resin (I-2a)”); a first pressure-sensitive adhesive composition(I-3) containing the pressure-sensitive adhesive resin (I-2a) and anenergy ray-curable low-molecular-weight compound; and the like.

{First Pressure-Sensitive Adhesive Composition (I-1)}

As described above, the first pressure-sensitive adhesive composition(I-1) contains the non-energy ray-curable pressure-sensitive adhesiveresin (I-1a) and an energy ray-curable compound.

(Pressure-Sensitive Adhesive Resin (I-1a))

The pressure-sensitive adhesive resin (I-1a) is preferably an acrylicresin.

Examples of the acrylic resin include acrylic polymers having at least aconstituent unit derived from an alkyl (meth)acrylate.

The acrylic resin may have only one type or two or more types ofconstituent units, and in a case of two or more types, the combinationand ratio thereof can be arbitrarily selected.

Examples of the alkyl (meth)acrylate include alkyl (meth)acrylates inwhich the number of carbon atoms in an alkyl group constituting thealkyl ester is 1 to 20, and the alkyl group is preferably a linear alkylgroup or a branched alkyl group.

More specific examples of the alkyl (meth)acrylate include methyl(meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl(meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate,sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl(meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate,2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl(meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, decyl(meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl(meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate(myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl(meth)acrylate (palmityl (meth)acrylate), heptadecyl (meth)acrylate,octadecyl (meth)acrylate (stearyl (meth)acrylate), nonadecyl(meth)acrylate, (meth)acrylate, and the like.

The acrylic polymer preferably has a constituent unit derived from analkyl (meth)acrylate in which the number of carbon atoms in the alkylgroup is four or more from the viewpoint that the pressure-sensitiveadhesive force of the first pressure-sensitive layer improves. Inaddition, the pressure-sensitive adhesive force of the firstpressure-sensitive adhesive layer further improves, the number of carbonatoms in the alkyl group is preferably 4 to 12 and more preferably 4 to8 from the viewpoint that the pressure-sensitive adhesive force of thefirst pressure-sensitive adhesive layer further improves. In addition,the alkyl (meth)acrylate in which the number of carbon atoms in thealkyl group is four or more is preferably alkyl acrylate.

The acrylic polymer preferably further has, in addition to theconstituent unit derived from the alkyl (meth)acrylate, a constituentunit derived from a functional group-containing monomer.

Examples of the functional group-containing monomer include monomers inwhich the functional group reacts with a crosslinking agent describedbelow and thus serves as a starting point of crosslinking or thefunctional group reacts with an unsaturated group in an unsaturatedgroup-containing compound and thus enables the introduction of theunsaturated group into a side chain of the acrylic polymer.

Examples of the functional group in the functional group-containingmonomer include a hydroxyl group, a carboxy group, an amino group, anepoxy group, and the like.

That is, examples of the functional group-containing monomer includehydroxyl group-containing monomers, carboxy group-containing monomers,amino group-containing monomers, epoxy group-containing monomers, andthe like.

Examples of the hydroxyl group-containing monomers include hydroxyalkyl(meth)acrylates such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl(meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl(meth)acrylate, and 4-hydroxybutyl (meth)acrylate; non-(meth)acrylicunsaturated alcohols such as vinyl alcohol and allyl alcohol(unsaturated alcohols not having a (meth)acryloyl skeleton); and thelike.

Examples of the carboxy group-containing monomers include ethylenicunsaturated monocarboxylic acids such as (meth)acrylic acid and crotonicacid (monocarboxylic acids having an ethylenic unsaturated bond);ethylenic unsaturated dicarboxylic acids such as fumaric acid, itaconicacid, maleic acid, and citraconic acid (dicarboxylic acids having anethylenic unsaturated bond); anhydrides of the ethylenic unsaturateddicarboxylic acid; carboxyalkyl (meth)acrylates such as 2-carboxyethylmethacrylate; and the like.

The functional group-containing monomer is preferably the hydroxylgroup-containing monomer or the carboxy group-containing monomer andmore preferably the hydroxyl group-containing monomer.

The acrylic polymer may be constituted of only one type or two or moretypes of the functional group-containing monomers. In a case in whichthe acrylic polymer is constituted of two or more types of thefunctional group-containing monomers, the combination and ratio thereofcan be arbitrarily selected.

In the acrylic polymer, the amount of the constituent unit derived fromthe functional group-containing monomer is preferably 1% to 35% by mass,more preferably 3% to 32% by mass, and particularly preferably 5% to 30%by mass of the mass of the constituent units.

The acrylic polymer may further have, in addition to the constituentunit derived from the alkyl (meth)acrylate and the constituent unitderived from the functional group-containing monomer, a constituent unitderived from a different monomer.

The different monomer is not particularly limited as long as the monomercan be copolymerized with the alkyl (meth)acrylate or the like.

Examples of the different monomer include styrene, α-methylstyrene,vinyl toluene, vinyl formate, vinyl acetate, acrylonitrile, acrylamide,and the like.

The different monomer constituting the acrylic polymer may beconstituted of only one type or two or more types of the functionalgroup-containing monomers. In a case in which the different monomerconstituting the acrylic polymer is constituted of two or more types ofthe functional group-containing monomers, the combination and ratiothereof can be arbitrarily selected.

The acrylic polymer can be used as the non-energy ray-curablepressure-sensitive adhesive resin (I-1a).

Meanwhile, a substance obtained by causing an unsaturatedgroup-containing compound having an energy ray-polymerizable unsaturatedgroup (energy ray-polymerizable group) to react with the functionalgroup in the acrylic polymer can be used as the energy ray-curablepressure-sensitive adhesive resin (I-2a).

Meanwhile, in the present invention, “being energy ray-polymerizable”refers to a property of being polymerized by being irradiated withenergy rays.

The first pressure-sensitive adhesive composition (I-1) may contain onlyone type or two or more types of the pressure-sensitive adhesive resin(I-1a). In a case in which the first pressure-sensitive adhesivecomposition (I-1) contains two or more types of the pressure-sensitiveadhesive resins (I-1a), the combination and ratio thereof can bearbitrarily selected.

In the first pressure-sensitive adhesive composition (I-1), the amountof the pressure-sensitive adhesive resin (I-1a) is preferably 5% to 99%by mass, more preferably 10% to 95% by mass, and particularly preferably15% to 90% by mass of the total mass of the first pressure-sensitiveadhesive composition (I-1).

(Energy Ray-Curable Compounds)

Examples of the energy ray-curable compound contained in the firstpressure-sensitive adhesive composition (I-1) include monomers oroligomers which have an energy ray-polymerizable unsaturated group andcan be cured by being irradiated with energy rays.

Among the energy ray-curable compounds, examples of monomers includepolyhydric (meth)acrylates such as trimethylol propanetri(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritoltetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butyleneglycol di(meth)acrylate, and 1,6-hexanediol (meth)acrylate; urethane(meth)acrylate; polyether (meth)acrylate; polyether (meth)acrylate;epoxy (meth)acrylate; and the like.

Among the energy ray-curable compounds, examples of oligomers includeoligomers obtained by polymerizing the monomers described as exemplaryexamples above.

The energy ray-curable compound is preferably urethane (meth)acrylate ora urethane (meth)acrylate oligomer since the molecular weight isrelatively great and the storage elastic modulus of the firstpressure-sensitive adhesive layer is not easily decreased.

The first pressure-sensitive adhesive composition (I-1) may contain onlyone type or two or more types of the energy ray-curable compounds. In acase in which the first pressure-sensitive adhesive composition (I-1)contains two or more types of the energy ray-curable compounds, thecombination and ratio thereof can be arbitrarily selected.

In the first pressure-sensitive adhesive composition (I-1), the amountof the energy ray-curable compound is preferably 1% to 95% by mass, morepreferably 5% to 90% by mass, and particularly preferably 10% to 85% bymass of the entire mass of the first pressure-sensitive adhesivecomposition (I-1).

(Crosslinking Agent)

In a case in which the acrylic polymer further having, in addition tothe constituent unit derived from the alkyl (meth)acrylate, theconstituent unit derived from the functional group-containing monomer asthe pressure-sensitive adhesive resin (I-1a), the firstpressure-sensitive adhesive composition (I-1) preferably furthercontains a crosslinking agent.

The crosslinking agent is, for example, a substance that reacts with thefunctional group and thus crosslinks the pressure-sensitive adhesiveresins (I-1a).

Examples of the crosslinking agent include isocyanate-based crosslinkingagents (crosslinking agents having an isocyanate group) such as tolylenediisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, andadduct bodies of the above-described diisocyanate; epoxy-basedcrosslinking agents (crosslinking agents having a glycidyl group) suchas ethylene glycol glycidyl ether; aziridine-based crosslinking agents(crosslinking agents having an aziridinyl group) such ashexa[1-(2-methyl)-aziridinyl]triphosphatriazine; metal chelate-basedcrosslinking agents (crosslinking agents having a metal chelatestructure) such as aluminum chelates; isocyanurate-based crosslinkingagents (crosslinking agents having an isocyanuric acid skeleton); andthe like.

The crosslinking agent is preferably the isocyanate-based crosslinkingagent since the isocyanate-based crosslinking agent improves thecohesive force of the pressure-sensitive adhesive so as to improve thepressure-sensitive adhesive force of the first pressure-sensitiveadhesive layer, is easily procurable, and the like.

The first pressure-sensitive adhesive composition (I-1) may contain onlyone type or two or more types of the crosslinking agents. In a case inwhich the first pressure-sensitive adhesive composition (I-1) containstwo or more types of the crosslinking agents, the combination and ratiothereof can be arbitrarily selected.

In the first pressure-sensitive adhesive composition (I-1), the amountof the crosslinking agent is preferably 0.01 to 50 parts by mass, morepreferably 0.1 to 20 parts by mass, and particularly preferably 1 to 10parts by mass of the amount (100 parts by mass) of thepressure-sensitive adhesive resin (I-1a).

(Photopolymerization Initiator)

The first pressure-sensitive adhesive composition (I-1) may also furthercontain a photopolymerization initiator. The first pressure-sensitiveadhesive composition (I-1) containing the photopolymerization initiatorsufficiently proceeds with a curing reaction even in a case of beingirradiated with energy rays having a relatively low energy such asultraviolet rays.

Examples of the photopolymerization initiator include benzoin compoundssuch as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoinisopropyl ether, benzoin isobutyl ether, benzoin benzoate, methylbenzoin benzoate, and benzoin dimethyl ketal; acetophenone compoundssuch as 2-hydroxy-2-methyl-1-phenyl-propane-1-one, and2,2-dimethoxy-1,2-diphenylethane-1-one; acylphosphine oxide compoundssuch as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide; sulfidecompounds such as benzylphenyl sulfide and tetramethylthiurammonosulfide; α-ketol compounds such as 1-hydroxycyclohexyl phenylketone; azo compounds such as azobisisobutyronitrile; titanocenecompounds such as titanocene; thioxanthone compounds such asthioxanthone; peroxide compounds; diketone compounds such as diacetyle;dibenzyl, and the like.

In addition, as the photopolymerization initiator, for example, aquinone compound such as 1-chloroanthraquinone; a photosensitizer suchas amine; or the like can also be used.

The first pressure-sensitive adhesive composition (I-1) may contain onlyone type or two or more types of the photopolymerization initiators. Ina case in which the first pressure-sensitive adhesive composition (I-1)contains two or more types of the photopolymerization initiators, thecombination and ratio thereof can be arbitrarily selected.

In the first pressure-sensitive adhesive composition (I-1), the amountof the photopolymerization initiator is preferably 0.01 to 20 parts bymass, more preferably 0.03 to 10 parts by mass, and particularlypreferably 0.05 to 5 parts by mass of the amount (100 parts by mass) ofthe energy ray-curable compound.

(Other Additives)

The first pressure-sensitive adhesive composition (I-1) may also containother additives which do not correspond to any of the above-describedcomponents as long as the effects of the present invention are notimpaired.

Examples of the other additives include a variety of well-knownadditives such as an antistatic agent, an antioxidant, a softening agent(plasticizer), a filler (filler), an antirust agent, a colorant (apigment or a dye), a sensitizer, a tackifier, a reaction retardant, anda crosslinking accelerator (catalyst).

Meanwhile, the reaction retardant is a substance that suppresses theprogress of an unintended crosslinking reaction in the firstpressure-sensitive adhesive composition (I-1) under storage due to, forexample, the action of the catalyst mixed into the firstpressure-sensitive adhesive composition (I-1). Examples of the reactionretardant include reaction retardants that form a chelate complex due toa chelate with respect to the catalyst, and more specific examplesthereof include substances having two or more carbonyl groups (—C(═O)—)in one molecule.

The first pressure-sensitive adhesive composition (I-1) may contain onlyone type or two or more types of other additives. In a case in which thefirst pressure-sensitive adhesive composition (I-1) contains two or moretypes of other additives, the combination and ratio thereof can bearbitrarily selected.

In the first pressure-sensitive adhesive composition (I-1), the amountof the other additives is not particularly limited and may beappropriately selected depending on the type of the additives.

(Solvent)

The first pressure-sensitive adhesive composition (I-1) may also containa solvent. When the first pressure-sensitive adhesive composition (I-1)contains a solvent, the coating aptitude to a coating target surfaceimproves.

The solvent is preferably an organic solvent, and examples of theorganic solvent include ketones such as methyl ethyl ketone and acetone;esters (carboxylic acid esters) such as ethyl acetate; ethers such astetrahydrofuran and dioxane; aliphatic hydrocarbons such as cyclohexaneand n-hexane; aromatic hydrocarbons such as toluene and xylene; alcoholssuch as 1-propanol and 2-propanol; and the like.

As the solvent, a solvent used during the manufacturing of thepressure-sensitive adhesive resin (I-1a) may be used in the firstpressure-sensitive adhesive composition (I-1) without being removed fromthe pressure-sensitive adhesive resin (I-1a). Alternatively, as thesolvent, a solvent of the same type as or a different type from thesolvent used during the manufacturing of the pressure-sensitive adhesiveresin (I-1a) may be separately added during the manufacturing of thefirst pressure-sensitive adhesive composition (I-1).

The first pressure-sensitive adhesive composition (I-1) may contain onlyone type or two or more types of the solvents. In a case in which thefirst pressure-sensitive adhesive composition (I-1) contains two or moretypes of the solvents, the combination and ratio thereof can bearbitrarily selected.

In the first pressure-sensitive adhesive composition (I-1), the amountof the solvent is not particularly limited and may be appropriatelyadjusted.

{First Pressure-Sensitive Adhesive Composition (I-2)}

As described above, the first pressure-sensitive adhesive composition(I-2) contains an energy ray-curable pressure-sensitive adhesive resin(I-2a) in which an unsaturated group is introduced into a side chain ofthe non-energy ray-curable pressure-sensitive adhesive resin (I-1a).

(Pressure-Sensitive Adhesive Resin (I-2a))

The pressure-sensitive adhesive resin (I-2a) can be obtained by, forexample, causing an unsaturated group-containing compound having anenergy ray-polymerizable unsaturated group to react with the functionalgroup in the pressure-sensitive adhesive resin (I-1a).

The unsaturated group-containing compound is a compound further having,in addition to the energy ray-polymerizable unsaturated group, a groupthat can be bonded with the pressure-sensitive adhesive resin (I-1a) byreacting with the functional group in the pressure-sensitive adhesiveresin (I-1a).

Examples of the energy ray-polymerizable unsaturated group include a(meth)acryloyl group, a vinyl group (ethenyl group), an allyl group(2-propenyl group), and the like, and a (meth)acryloyl group ispreferred.

Examples of the group that can be bonded with the functional group inthe pressure-sensitive adhesive resin (I-1a) include isocyanate groupsand glycidyl groups that can be bonded with a hydroxyl group or an aminogroup, hydroxyl groups and amino groups that can be bonded with acarboxy group or an epoxy group, and the like.

Examples of the unsaturated group-containing compound include(meth)acryloyloxyethyl isocyanate, (meth)acryloyl isocyanate, glycidyl(meth)acrylate, and the like.

The first pressure-sensitive adhesive composition (I-2) may contain onlyone type or two or more types of the pressure-sensitive adhesive resin(I-2a). In a case in which the first pressure-sensitive adhesivecomposition (I-2) contains two or more types of the pressure-sensitiveadhesive resins (I-2a), the combination and ratio thereof can bearbitrarily selected.

In the first pressure-sensitive adhesive composition (I-2), the amountof the pressure-sensitive adhesive resin (I-2a) is preferably 5% to 99%by mass, more preferably 10% to 95% by mass, and particularly preferably10% to 90% by mass of the total mass of the first pressure-sensitiveadhesive composition (I-2).

(Crosslinking Agent)

In a case in which, as the pressure-sensitive adhesive resin (I-2a), forexample, the acrylic polymer having the constituent unit derived fromthe functional group-containing monomer, which is the same as that inthe pressure-sensitive adhesive resin (I-1a) is used, the firstpressure-sensitive adhesive composition (I-2) may further contain acrosslinking agent.

Examples of the crosslinking agent in the first pressure-sensitiveadhesive composition (I-2) include the same crosslinking agents as thosein the first pressure-sensitive adhesive composition (I-1).

The first pressure-sensitive adhesive composition (I-2) may contain onlyone type or two or more types of the crosslinking agents. In a case inwhich the first pressure-sensitive adhesive composition (I-2) containstwo or more types of the crosslinking agents, the combination and ratiothereof can be arbitrarily selected.

In the first pressure-sensitive adhesive composition (I-2), the amountof the crosslinking agent is preferably 0.01 to 50 parts by mass, morepreferably 0.1 to 20 parts by mass, and particularly preferably 1 to 10parts by mass of the amount (100 parts by mass) of thepressure-sensitive adhesive resin (I-2a).

(Photopolymerization Initiator)

The first pressure-sensitive adhesive composition (I-2) may also furthercontain a photopolymerization initiator. The first pressure-sensitiveadhesive composition (I-2) containing the photopolymerization initiatorsufficiently proceeds with a curing reaction even in a case of beingirradiated with energy rays having a relatively low energy such asultraviolet rays.

Examples of the photopolymerization initiator in the firstpressure-sensitive adhesive composition (I-2) include the samephotopolymerization initiators as those in the first pressure-sensitiveadhesive composition (I-1).

The first pressure-sensitive adhesive composition (I-2) may contain onlyone type or two or more types of the photopolymerization initiators. Ina case in which the first pressure-sensitive adhesive composition (I-2)contains two or more types of the photopolymerization initiators, thecombination and ratio thereof can be arbitrarily selected.

In the first pressure-sensitive adhesive composition (I-2), the amountof the photopolymerization initiator is preferably 0.01 to 20 parts bymass, more preferably 0.03 to 10 parts by mass, and particularlypreferably 0.05 to 5 parts by mass of the amount (100 parts by mass) ofthe pressure-sensitive adhesive resin (I-2a).

(Other Additives)

The first pressure-sensitive adhesive composition (I-2) may also containother additives which do not correspond to any of the above-describedcomponents as long as the effects of the present invention are notimpaired.

Examples of the other additives in the first pressure-sensitive adhesivecomposition (I-2) include the same other additives as those in the firstpressure-sensitive adhesive composition (I-1).

The first pressure-sensitive adhesive composition (I-2) may contain onlyone type or two or more types of other additives. In a case in which thefirst pressure-sensitive adhesive composition (I-2) contains two or moretypes of other additives, the combination and ratio thereof can bearbitrarily selected.

In the first pressure-sensitive adhesive composition (I-2), the amountof the other additives is not particularly limited and may beappropriately selected depending on the type of the additives.

(Solvent)

The first pressure-sensitive adhesive composition (I-2) may also containa solvent for the same purpose as in the case of the firstpressure-sensitive adhesive composition (I-1).

Examples of the solvent in the first pressure-sensitive adhesivecomposition (I-2) include the same solvents as those in the firstpressure-sensitive adhesive composition (I-1).

The first pressure-sensitive adhesive composition (I-2) may contain onlyone type or two or more types of the solvents. In a case in which thefirst pressure-sensitive adhesive composition (I-2) contains two or moretypes of the solvents, the combination and ratio thereof can bearbitrarily selected.

In the first pressure-sensitive adhesive composition (I-2), the amountof the solvent is not particularly limited and may be appropriatelyadjusted.

{First Pressure-Sensitive Adhesive Composition (I-3)}

As described above, the first pressure-sensitive adhesive composition(I-3) contains the pressure-sensitive adhesive resin (I-2a) and anenergy ray-curable low-molecular-weight compound.

In the first pressure-sensitive adhesive composition (I-3), the amountof the pressure-sensitive adhesive resin (I-2a) is preferably 5% to 99%by mass, more preferably 10% to 95% by mass, and particularly preferably15% to 90% by mass of the total mass of the first pressure-sensitiveadhesive composition (I-3).

(Energy Ray-Curable Low-Molecular-Weight Compound)

Examples of the energy ray-curable low-molecular-weight compoundcontained in the first pressure-sensitive adhesive composition (I-3)include monomers or oligomers which have an energy ray-polymerizableunsaturated group and can be cured by being irradiated with energy raysand include the same energy ray-curable compounds as that in the firstpressure-sensitive adhesive composition (I-1).

The first pressure-sensitive adhesive composition (I-3) may contain onlyone type or two or more types of the energy ray-curablelow-molecular-weight compounds. In a case in which the firstpressure-sensitive adhesive composition (I-3) contains two or more typesof the energy ray-curable low-molecular-weight compounds, thecombination and ratio thereof can be arbitrarily selected.

In the first pressure-sensitive adhesive composition (I-3), the amountof the energy ray-curable low-molecular-weight compound is preferably0.01 to 300 parts by mass, more preferably 0.03 to 200 parts by mass,and particularly preferably 0.05 to 100 parts by mass of the amount (100parts by mass) of the pressure-sensitive adhesive resin (I-2a).

(Photopolymerization Initiator)

The first pressure-sensitive adhesive composition (I-3) may also furthercontain a photopolymerization initiator. The first pressure-sensitiveadhesive composition (I-3) containing the photopolymerization initiatorsufficiently proceeds with a curing reaction even when irradiated withenergy rays having a relatively low energy such as ultraviolet rays.

Examples of the photopolymerization initiator in the firstpressure-sensitive adhesive composition (I-3) include the samephotopolymerization initiators as those in the first pressure-sensitiveadhesive composition (I-1).

The first pressure-sensitive adhesive composition (I-3) may contain onlyone type or two or more types of the photopolymerization initiators. Ina case in which the first pressure-sensitive adhesive composition (I-3)contains two or more types of the photopolymerization initiators, thecombination and ratio thereof can be arbitrarily selected.

In the first pressure-sensitive adhesive composition (I-3), the amountof the photopolymerization initiator is preferably 0.01 to 20 parts bymass, more preferably 0.03 to 10 parts by mass, and particularlypreferably 0.05 to 5 parts by mass of the total amount (100 parts bymass) of the pressure-sensitive adhesive resin (I-2a) and the energyray-curable low-molecular-weight compound.

(Other Additives)

The first pressure-sensitive adhesive composition (I-3) may also containother additives which do not correspond to any of the above-describedcomponents as long as the effects of the present invention are notimpaired.

Examples of the other additives include the same other additives asthose in the first pressure-sensitive adhesive composition (I-1).

The first pressure-sensitive adhesive composition (I-3) may contain onlyone type or two or more types of other additives. In a case in which thefirst pressure-sensitive adhesive composition (I-3) contains two or moretypes of other additives, the combination and ratio thereof can bearbitrarily selected.

In the first pressure-sensitive adhesive composition (I-3), the amountof the other additives is not particularly limited and may beappropriately selected depending on the type of the additives.

(Solvent)

The first pressure-sensitive adhesive composition (I-3) may also containa solvent for the same purpose as in the case of the firstpressure-sensitive adhesive composition (I-1).

Examples of the solvent in the first pressure-sensitive adhesivecomposition (I-3) include the same solvents as those in the firstpressure-sensitive adhesive composition (I-1).

The first pressure-sensitive adhesive composition (I-3) may contain onlyone type or two or more types of the solvents. In a case in which thefirst pressure-sensitive adhesive composition (I-3) contains two or moretypes of the solvents, the combination and ratio thereof can bearbitrarily selected.

In the first pressure-sensitive adhesive composition (I-3), the amountof the solvent is not particularly limited and may be appropriatelyadjusted.

{First Pressure-Sensitive Adhesive Compositions Other Than FirstPressure-Sensitive Adhesive Compositions (I-1) to (I-3)}

Hitherto, the first pressure-sensitive adhesive composition (I-1), thefirst pressure-sensitive adhesive composition (I-2), and the firstpressure-sensitive adhesive composition (I-3) have been mainlydescribed, but the substances described as the contained componentsthereof can also be used in the same manner in general firstpressure-sensitive adhesive compositions other than the above-describedthree types of first pressure-sensitive adhesive compositions (in thepresent embodiment, referred to as the first pressure-sensitive adhesivecompositions other than the first pressure-sensitive adhesivecompositions (I-1) to (I-3)).

Examples of the first pressure-sensitive adhesive compositions otherthan the first pressure-sensitive adhesive compositions (I-1) to (I-3)include, in addition to, the first energy ray-curable pressure-sensitiveadhesive compositions, a first non-energy ray-curable pressure-sensitiveadhesive composition.

Examples of the first non-energy ray-curable pressure-sensitive adhesivecompositions include non-energy ray-curable pressure-sensitive adhesivecompositions containing a pressure-sensitive adhesive resin such as anacrylic resin (a resin having a (meth)acryloyl group), an urethane-basedresin (a resin having a urethane bond), a rubber-based resin (a resinhaving a rubber structure), a silicone-based resin (a resin having asiloxane bond), an epoxy-based resin (a resin having an epoxy group), apolyvinyl ether, or a polycarbonate, and non-energy ray-curablepressure-sensitive adhesive compositions containing an acrylic resin arepreferred.

The first pressure-sensitive adhesive compositions other than the firstpressure-sensitive adhesive compositions (I-1) to (I-3) preferablycontain one or more types of crosslinking agents, and the amount thereofcan be set to be the same as that in the case of the above-describedfirst pressure-sensitive adhesive composition (I-1) or the like.

<Method for Manufacturing First Pressure-Sensitive Adhesive Composition>

The first pressure-sensitive adhesive compositions such as the firstpressure-sensitive adhesive compositions (I-1) to (I-3) can be obtainedby blending individual components for constituting the firstpressure-sensitive adhesive compositions such as the pressure-sensitiveadhesive, components other than the pressure-sensitive adhesive asnecessary, and the like.

The addition order during the blending of the respective components isnot particularly limited, and two or more types of components may beadded at the same time.

In a case in which the solvent is used, the solvent may be used bymixing the solvent with all of the blending components other than thesolvent so as to dilute these blending components in advance or may beused by mixing the solvent with the blending components without dilutingall of the blending components other than the solvent in advance.

A method for mixing the respective components during blending is notparticularly limited and may be appropriately selected from well-knownmethods such as a method in which the components are mixed together byrotating a stirring stick, a stirring blade, or the like; a method inwhich the components are mixed together using a mixer, and a method inwhich the components are mixed together by applying ultrasonic wavesthereto.

The temperature and the time during the addition and mixing of therespective components are not particularly limited as long as therespective blending components do not deteriorate and may beappropriately adjusted, but the temperature is preferably 15° C. to 30°C.

[First Interlayer]

The first interlayer has a sheet form or a film form, and a constituentmaterial thereof may be appropriately selected depending on the purposeand is not particularly limited.

For example, in a case in which the purpose is to suppress thedeformation of the first protective film by reflecting the shape ofbumps present on a semiconductor surface in the first protective filmthat covers the semiconductor surface, examples of a preferredconstituent material of the first interlayer include urethane(meth)acrylate and the like from the viewpoint of further improving theattachment property of the first interlayer.

The first interlayer may be a single layer (monolayer) or a plurality oftwo or more layers. In a case in which the first interlayer is aplurality of layers, the respective layers in the plurality of layersmay be identical to or different from one another, and the combinationof the plurality of layers is not particularly limited.

The thickness of the first interlayer can be appropriately adjusteddepending on the height of bumps on the semiconductor surface which is aprotection target, but is preferably 50 to 600 μm, more preferably 70 to500 μm, and particularly preferably 80 to 400 μm since it is possible torelatively easily absorb the influence of bumps having a relatively highheight.

Here, “the thickness of the first interlayer” refers to the thickness ofthe entire first interlayer, and, for example, the thickness of thefirst interlayer made up of a plurality of layers refers to the totalthickness of all of the layers constituting the first interlayer.

{{First Interlayer Forming Composition}}

The first interlayer can be formed using a first interlayer formingcomposition containing the constituent material.

For example, the first interlayer can be formed at an intended portionby applying the first interlayer forming composition to a target surfaceon which the first interlayer is to be formed and drying the firstinterlayer forming composition or curing the first interlayer formingcomposition by being irradiated with energy rays as necessary. A morespecific method for forming the first interlayer will be described belowin detail together with methods for forming other layers. The ratiobetween the amounts of components, which do not gasify at normaltemperature, in the first interlayer forming composition is, generally,identical to the ratio between the amounts of the above-describedcomponents in the first interlayer. Here, “normal temperature” is asdescribed above.

The first interlayer forming composition may be applied using awell-known method, and examples thereof include methods in which avariety of coaters such as an air knife coater, a blade coater, a barcoater, a gravure coater, a roll coater, a roll knife coater, a curtaincoater, a die coater, a knife coater, a screen coater, a Mayer barcoater, and a kiss coater are used.

The drying conditions of the first interlayer forming composition arenot particularly limited; however, in a case in which the firstinterlayer forming composition contains a solvent described below, thefirst interlayer forming composition is preferably heated and dried,and, in this case, the first interlayer forming composition ispreferably dried under conditions of, for example, 70° C. to 130° C. and10 seconds to 5 minutes.

In a case in which the first interlayer forming composition is energyray-curable, the first interlayer forming composition is preferablyfurther cured by being irradiated with energy rays after drying.

Examples of the first interlayer forming composition include a firstinterlayer forming composition containing urethane (meth)acrylate (II-1)and the like.

{First Interlayer Forming Composition (II-1)}

As described above, the first interlayer forming composition (II-1)contains urethane (meth)acrylate.

(Urethane (Meth)acrylate)

The urethane (meth)acrylate is a compound having at least a(meth)acryloyl group and a urethane bond in one molecule and is energyray-polymerizable.

The urethane (meth)acrylate may be a monofunctional urethane(meth)acrylate (urethane (meth)acrylate having only one (meth)acryloylgroup in one molecule) or may be a di- or higher-functional urethane(meth)acrylate (urethane (meth)acrylate having two or more(meth)acryloyl groups in one molecule), that is, a multifunctionalurethane (meth)acrylate, but urethane (meth)acrylate having at least one(meth)acryloyl group is preferably used.

Examples of the urethane (meth)acrylate contained in the firstinterlayer forming composition include urethane (meth)acrylate obtainedby further causing a (meth)acrylic compound having a hydroxyl group anda (meth)acryloyl group to react with a terminal isocyanate urethaneprepolymer obtained by reacting a polyol compound and a polyhydricisocyanate compound. Here, “the terminal isocyanate urethane prepolymer”refers to a prepolymer having a urethane bond and having an isocyanategroup at a terminal portion of the molecule.

The first interlayer forming composition (II-1) may contain only onetype or two or more types of the urethane (meth)acrylate. In a case inwhich the first interlayer forming composition (II-1) contains two ormore types of the urethane (meth)acrylate, the combination and ratiothereof can be arbitrarily selected.

(A) Polyol Compound

The polyol compound is not particularly limited as long as the compoundhas two or more hydroxyl groups in one molecule.

One type of the polyol compound may be used singly or two or more typesof the polyol compounds may be used in combination. In a case in whichtwo or more types of the polyol compounds are used in combination, thecombination and ratio thereof can be arbitrarily selected.

Examples of the polyol compound include alkylenediol, polyether-typepolyols, polyester-type polyols, polycarbonate-type polyols, and thelike.

The polyol compound may be any one of a difunctional diol, atrifunctional triol, and tetra- or higher-functional polyols, but a diolis preferred since the diol can be easily procured and is excellent interms of versatility, reactivity, and the like.

Polyether-Type Polyol

The polyether-type polyol is not particularly limited, but is preferablya polyether-type diol, and examples of the polyether-type diol includecompounds represented by General Formula (1).

HOR—O_(n)H  (1)

(Here, in Formula (1), n represents an integer of 2 or more; Rrepresents a divalent hydrocarbon group, and a plurality of R's may beidentical to or different from one another)

In Formula (1), n represents the number of repeating units of a grouprepresented by General Formula “—R—O—” and is not particularly limitedas long as n is an integer of 2 or more. Among these, n is preferably 10to 250, more preferably 25 to 205, and particularly preferably 40 to185.

In Formula (1), R is not particularly limited as long as R is a divalenthydrocarbon group, but is preferably an alkylene group, more preferablyan alkylene group having 1 to 6 carbon atoms, still more preferably anethylene group, a propylene group, or a tetramethylene group, andparticularly preferably a propylene group or a tetramethylene group.

The compound represented by Formula (1) is preferably polyethyleneglycol, polypropylene glycol or polytetramethylene glycol and morepreferably polypropylene glycol or polytetramethylene glycol.

When the polyether-type diol and the polyhydric isocyanate compound arereacted with each other, urethane (meth)acrylate having an ether bondportion represented by General Formula (1a) as the terminal isocyanateurethane prepolymer can be obtained. In addition, when theabove-described terminal isocyanate urethane prepolymer is used, theurethane (meth)acrylate has the ether bond portion, that is, has aconstituent unit derived from the polyether-type diol.

R—O_(n)  (1a)

(Here, in Formula (1a), R and n are the same as described above)

Polyester-Type Polyol

The polyester-type polyol is not particularly limited, and examplesthereof include polyols obtained by causing an esterification reactionusing a polybasic acid or a derivative thereof, and the like. Meanwhile,in the present embodiment, unless particularly otherwise described, “aderivative” refers to a compound in which one or more groups aresubstituted with other groups (substituents). Here, “a group” refers notonly to an atomic group formed by bonding a plurality of atoms but alsoto one atom.

Examples of the polybasic acid or the derivative thereof includepolybasic acids that are ordinarily used as a manufacturing raw materialof polyesters and derivatives thereof.

Examples of the polybasic acids include saturated aliphatic polybasicacids, unsaturated aliphatic polybasic acids, aromatic polybasic acids,and the like, and dimers corresponding to any of the above-describedpolybasic acids may also be used.

Examples of the saturated aliphatic polybasic acids include saturatedaliphatic dibasic acids such as oxalic acid, malonic acid, succinicacid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaicacid, and sebacic acid, and the like.

Examples of the unsaturated aliphatic polybasic acids includeunsaturated aliphatic dibasic acids such as maleic acid and fumaricacid.

Examples of the aromatic polybasic acids include aromatic dibasic acidssuch as phthalic acid, isophthalic acid, terephthalic acid, and2,6-naphthalenedicarboxylic acid; aromatic tribasic acids such astrimellitic acid; aromatic tetrabasic acids such as pyromellitic acid;and the like.

Examples of the derivatives of the polybasic acids include acidanhydrides of the saturated aliphatic polybasic acids, the unsaturatedaliphatic polybasic acids, and the aromatic polybasic acids describedabove, hydrogenated dimer acids, and the like.

One type of the polybasic acid or a derivative thereof may be usedsingly or two or more types of the polyol compounds may be used incombination. In a case in which two or more types of the polybasic acidor the derivative are used in combination, the combination and ratiothereof can be arbitrarily selected.

The polybasic acid is preferably the aromatic polybasic acid since thearomatic polybasic acid is suitable for the formation of coated filmshaving an appropriate hardness.

In the esterification reaction for obtaining the polyester-type polyol,a well-known catalyst may also be used as necessary.

Examples of the catalyst include tin compounds such as dibutyltin oxideand stannous octanoate; alkoxy titanium such as tetrapropyl titanate;and the like.

Polycarbonate-Type Polyol

The polycarbonate-type polyol is not particularly limited, and examplesthereof include polycarbonates obtained by reacting the same glycol asthe compound represented by Formula (1) and alkylene carbonate, and thelike.

Here, one type of glycol and alkylene carbonate may be used singly ortwo or more types thereof may be used in combination. In a case in whichtwo or more types of the glycol and alkylene carbonate are used incombination, the combination and ratio thereof can be arbitrarilyselected.

The number-average molecular weight computed from the hydroxyl value ofthe polyol compound is preferably 1,000 to 10,000, more preferably 2,000to 9,000, and particularly preferably 3,000 to 7,000. When thenumber-average molecular weight is 1,000 or more, the excess generationof urethane bonds is suppressed, and it becomes easier to suppress theviscoelastic characteristic of the first interlayer. In addition, whenthe number-average molecular weight is 10,000 or less, the excesssoftening of the first interlayer is suppressed.

The number-average molecular weight computed from the hydroxyl value ofthe polyol compound refers to a value computed from the followingexpression.

[The number-average molecular weight of the polyol compound]=[the numberof functional groups in the polyol compound]×56.11×1,000/[the hydroxylvalue of the polyol compound (unit: mgKOH/g)]

The polyol compound is preferably the polyether-type polyol and morepreferably a polyether-type diol.

(B) Polyhydric Isocyanate Compound

The polyhydric isocyanate compound that is reacted with the polyolcompound is not particularly limited as long as the polyhydricisocyanate compound has two or more isocyanate groups.

One type of the polyhydric isocyanate compound may be used singly or twoor more types of the polyhydric isocyanate compounds may be used incombination. In a case in which two or more types of the polyhydricisocyanate compounds are used in combination, the combination and ratiothereof can be arbitrarily selected.

Examples of the polyhydric isocyanate compound include chain-likediisocyanates such as tetramethylene diisocyanate, hexamethylenediisocyanate, and trimethylhexamethylene diisocyanate; cyclic aliphaticdiisocyanates such as isophorone diisocyanate, norbornane diisocyanate,dicyclohexylmethane-4,4′-diisocyanate,dicyclohexylmethane-2,4′-diisocyanate, and ω,ω′-diisocyanatedimethylcyclohexane; aromatic diisocyanates such as 4,4′-diphenylmethanediisocyanate, tolylene diisocyanate, xylylene diisocyanate, tolylenediisocyanate, tetramethylene xylylene diisocyanate, andnaphthalene-1,5-diisocyanate; and the like.

Among these, the polyhydric isocyanate compound is preferably isophoronediisocyanate, hexamethylene diisocyanate, or xylylene diisocyanate fromthe viewpoint of the handling property.

(C) (Meth)acrylic Compound

The (meth)acrylic compound that is reacted with the terminal isocyanateurethane prepolymer is not particularly limited as long as the compoundhas at least a hydroxyl group and a (meth)acryloyl group in onemolecule.

One type of the (meth)acrylic compound may be used singly or two or moretypes of the (meth)acrylic compounds may be used in combination. In acase in which two or more types of the (meth)acrylic compounds are usedin combination, the combination and ratio thereof can be arbitrarilyselected.

Examples of the (meth)acrylic compound include hydroxyl group-containing(meth)acrylic acid esters such as 2-hyroxyethyle (meth)acrylate,2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate,2-hyroxybutyl (meth)acrylate, 3-hyroxybuyl (meth)acrylate,4-hydroxybutyl (meth)acrylate, 4-hydroxycyclohexyl (meth)acrylate,5-hydroxycyclooxtyl (meth)acrylate, 2-hydroxy-3-phenyloxypropyl(meth)acrylate, pentaerythritol tri(meth)acrylate, polyethylene glycolmono(meth)acrylate, and polypropylene glycol mono(meth)acrylate;hydroxyl group-containing (meth)acrylamides such as N-methylol(meth)acrylamide; reactants obtained by reacting (meth)acrylic acid withvinyl alcohol, vinyl phenol, or bisphenol A glycidyl ether; and thelike.

Among these, the (meth)acrylic compound is preferably the hydroxylgroup-containing (meth)acrylic acid ester, more preferably a hydroxylgroup-containing alkyl (meth)acrylate, and particularly preferably2-hydroxyethyl (meth)acrylate.

The reaction between the terminal isocyanate urethane prepolymer and the(meth)acrylic compound may be caused using a solvent, a catalyst, andthe like as necessary.

Conditions during the reaction between the terminal isocyanate urethaneprepolymer and the (meth)acrylic compound may be appropriately adjusted,and, for example, the reaction temperature is preferably 60° C. to 100°C., and the reaction time is preferably one to four hours.

The urethane (meth)acrylate may be any of an oligomer, a polymer and amixture of an oligomer and a polymer and is preferably an oligomer.

For example, the weight-average molecular weight of the urethane(meth)acrylate is preferably 1,000 to 100,000, more preferably 3,000 to80,000, and particularly preferably 5,000 to 65,000. When theweight-average molecular weight of the weight-average molecular weightof the urethane (meth)acrylate is 1,000 or more, it becomes easy tooptimize the hardness of the first interlayer due to the intermolecularforce between structures derived from the urethane (meth)acrylate inpolymers of the urethane (meth)acrylate and a polymerizable monomerdescribed below.

(Polymerizable Monomer)

The first interlayer forming composition (II-1) may also contain, inaddition to the urethane (meth)acrylate, a polymerizable monomer fromthe viewpoint of further improving the film-forming property.

The polymerizable monomer refers to polymerizable monomers except foroligomers and polymers which are energy ray-polymerizable and have aweight-average molecular weight of 1,000 or more and is preferably acompound having at least one (meth)acryloyl group in one molecule.

Examples of the polymerizable monomer include alkyl (meth)acrylates inwhich an alkyl group constituting the alkyl ester has 1 to 30 carbonatoms and has a chain-like shape; functional group-containing(meth)acrylic compounds having a functional group such as a hydroxylgroup, an amide group, an amino group, or an epoxy group; (meth)acrylicacid esters having an aliphatic cyclic group; (meth)acrylic acid estershaving an aromatic hydrocarbon group; (meth)acrylic acid esters having aheterocyclic group; compounds having a vinyl group; compounds having anallyl group; and the like.

Examples of the alkyl (meth)acrylates having a chain-like alkyl grouphaving 1 to 30 carbon atoms include methyl (meth)acrylate, ethyl(meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate,n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl(meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl(meth)acrylate, heptyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl(meth)acrylate, 2-ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate,isononyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate,dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate,tetradecyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl(meth)acrylate, hexadecyl (meth)acrylate (palmityl (meth)acrylate),heptadecyl (meth)acrylate, octadecyl (meth)acrylate (stearyl(meth)acrylate), isooctadecyl (meth)acrylate (isostearyl(meth)acrylate), nonadecyl (meth)acrylate, icosyl (meth)acrylate, andthe like.

Examples of functional group-containing (meth)acrylic derivativesinclude hydroxyl group-containing (meth)acrylic acid esters such as2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate,3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate,3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate;(meth)acrylamides such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl (meth)acrylamide, N-methylol (meth)acrylamide,N-methylolpropane (meth)acrylamide, N-methoxymethyl (meth)acrylamide,and N-butoxymethyl (meth)acrylamide and derivatives thereof;(meth)acrylic acid esters having an amino group (hereinafter, in somecases, referred to as “the amino group-containing (meth)acrylic acidesters”); (meth)acrylic acid esters having a monosubstituted amino groupwhich are formed by substituting one hydrogen atom in an amino groupwith a group other than a hydrogen atom (hereinafter, in some cases,referred to as “the monosubstituted amino group-containing (meth)acrylicacid esters”); (meth)acrylic acid esters having a disubstituted aminogroup which are formed by substituting two hydrogen atoms in an aminogroup with groups other than a hydrogen atom (hereinafter, in somecases, referred to as “the disubstituted amino group-containing(meth)acrylic acid esters”); (meth)acrylic acid esters having an epoxygroup such as glycidyl (meth)acrylate and methyl glycidyl (meth)acrylate(hereinafter, in some cases, referred to as “the epoxy group-containing(meth)acrylic acid esters”); and the like.

Here, “the amino group-containing (meth)acrylic acid ester” refers to acompound formed by substituting one or more hydrogen atoms in a(meth)acrylic acid ester with an amino group (—NH₂). Similarly, “themonosubstituted amino group-containing (meth)acrylic acid ester” refersto a compound formed by substituting one or more hydrogen atoms in a(meth)acrylic acid ester with a monosubstituted amino group, and “thedisubstituted amino group-containing (meth)acrylic acid ester” refers toa compound formed by substituting one or more hydrogen atoms in a(meth)acrylic acid ester with a disubstituted amino group.

Examples of the group other than a hydrogen atom which substitutes thehydrogen atom (that is, the substituent) in “the monosubstituted aminogroup” and “the disubstituted amino group” include alkyl groups and thelike.

Examples of the (meth)acrylic acid esters having an aliphatic cyclicgroup include isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate,dicyclopentanyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate,cyclohexyl (meth)acrylate, adamantyl (meth)acrylate, and the like.

Examples of the (meth)acrylic acid esters having an aromatic hydrocarbongroup include phenyl hydroxypropyl (meth)acrylate, benzyl(meth)acrylate, 2-hyroxy-3-phenoxypropyl (meth)acrylate, and the like.

The heterocyclic group in the (meth)acrylic acid ester having aheterocyclic group may be any of an aromatic heterocyclic group and analiphatic heterocyclic group.

Examples of the (meth)acrylic acid esters having the heterocyclic groupinclude tetrahydrofurfuryl (meth)acrylate, (meth)acryloyl morpholine,and the like.

Examples of the compounds having a vinyl group include styrene,hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, N-vinylformamide,N-vinylpyrrolidone, N-vinylcaprolactam, and the like.

Examples of the compounds having an allyl group include allyl glycidylethers and the like.

The polymerizable monomer preferably has a group having a relativelylarge volume since the compatibility with the urethane (meth)acrylate isfavorable. Examples of the polymerizable monomer include (meth)acrylicacid esters having an aliphatic cyclic group, (meth)acrylic acid estershaving an aromatic hydrocarbon group, and (meth)acrylic acid estershaving a heterocyclic group, and (meth)acrylic acid esters having analiphatic cyclic group are more preferred.

The first interlayer forming composition (II-1) may contain only onetype or two or more types of the polymerizable monomers. In a case inwhich the first interlayer forming composition (II-1) contains two ormore types of the polymerizable monomers, the combination and ratiothereof can be arbitrarily selected.

In the first interlayer forming composition (II-1), the amount of thepolymerizable monomer is preferably 10% to 99% by mass, more preferably15% to 95% by mass, still more preferably 20% to 90% by mass, andparticularly preferably 25% to 80% by mass of the total mass of thefirst interlayer forming composition (II-1).

(Photopolymerization Initiator)

The first interlayer forming composition (II-1) may also contain, inaddition to the urethane (meth)acrylate and the polymerizable monomer, aphotopolymerization initiator. The first interlayer forming composition(II-1) containing the photopolymerization initiator sufficientlyproceeds with a curing reaction even in a case of being irradiated withenergy rays having a relatively low energy such as ultraviolet rays.

Examples of the photopolymerization initiator include benzoin compoundssuch as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoinisopropyl ether, benzoin isobutyl ether, benzoin benzoate, methylbenzoin benzoate, and benzoin dimethyl ketal; acetophenone compoundssuch as 2-hydroxy-2-methyl-1-phenyl-propane-1-one, and2,2-dimethoxy-1,2-diphenylethane-1-one; acylphosphine oxide compoundssuch as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide; sulfidecompounds such as benzylphenyl sulfide and tetramethylthiurammonosulfide; α-ketol compounds such as 1-hydroxycyclohexyl phenylketone; azo compounds such as azobisisobutylonitrile; titanocenecompounds such as titanocene; thioxanthone compounds such asthioxanthone; peroxide compounds; diketone compounds such as diacetyle;dibenzyl, and the like.

In addition, as the photopolymerization initiator, for example, aquinone compound such as 1-chloroanthraquinone; a photosensitizer suchas amine; or the like can also be used.

The first interlayer forming composition (II-1) may contain only onetype or two or more types of the photopolymerization initiators. In acase in which the first interlayer forming composition (II-1) containstwo or more types of the photopolymerization initiators, the combinationand ratio thereof can be arbitrarily selected.

In the first interlayer forming composition (II-1), the amount of thephotopolymerization initiator is preferably 0.01 to 20 parts by mass,more preferably 0.03 to 10 parts by mass, and particularly preferably0.05 to 5 parts by mass of the total amount (100 parts by mass) of theurethane (meth)acrylate and the polymerizable monomer.

(Resin Components Other than Urethane (Meth)Acrylate)

The first interlayer forming composition (II-1) may also contain resincomponents other than the urethane (meth)acrylate as long as the effectsof the present invention are not impaired.

The types of the resin components and the amount thereof in the firstinterlayer forming composition (II-1) may be appropriately selecteddepending on the purpose and are not particularly limited.

(Other Additives)

The first interlayer forming composition (II-1) may also contain otheradditives which do not correspond to any of the above-describedcomponents as long as the effects of the present invention are notimpaired.

Examples of the other additives include a variety of well-knownadditives such as a crosslinking agent, an antistatic agent, anantioxidant, a chain transfer, a softening agent (plasticizer), afiller, an antirust agent, and a colorant (a pigment or a dye).

Examples of the chain transfer include thiol compounds having at leastone thiol group (mercapto group) in one molecule.

Examples of the thiol compounds include nonyl mercaptan,1-dodecanethiol, 1,2-ethanedithiol, 1,3-propandithiol, triazinethiol,triazinedithiol, triazinetrithiol, 1,2,3-propanetrithiol, tetraethyleneglycol bis(3-mercaptopropionate), trimethylolpropanetris(3-mercaptopropionate), pentaerythritoltetrakis(3-mercaptopropionate), pentaerythritol tetrakisthioglycolate,dipentaerythritol hexakis(3-mercaptopropionate),tris[(3-mercaptopropioniloxy)-ethyl]-isocyanurate,1,4-bis(3-mercaptobutyryloxy)butane, pentaerythritoltetrakis(3-mercaptobutylate),1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione,and the like.

The first interlayer forming composition (II-1) may contain only onetype or two or more types of other additives. In a case in which thefirst interlayer forming composition (II-1) contains two or more typesof the other additives, the combination and ratio thereof can bearbitrarily selected.

In the first interlayer forming composition (II-1), the amount of theother additives is not particularly limited and may be appropriatelyselected depending on the type of the additives.

(Solvent)

The first interlayer forming composition (II-1) may also contain asolvent. When the first interlayer forming composition (II-1) contains asolvent, the coating aptitude to a coating target surface improves.

{{Method for Manufacturing First Interlayer Forming Composition}}

The first interlayer forming composition such as the first interlayerforming composition (II-1) can be obtained by blending individualcomponents for constituting the first interlayer forming composition.

The addition order during the blending of the respective components isnot particularly limited, and two or more types of components may beadded at the same time.

In a case in which the solvent is used for the first interlayer formingcomposition, the solvent may be used by mixing the solvent with all ofthe blending components other than the solvent so as to dilute theseblending components in advance or may be used by mixing the solvent withthe blending components without diluting all of the blending componentsother than the solvent in advance.

A method for mixing the respective components during blending is notparticularly limited and may be appropriately selected from well-knownmethods such as a method in which the components are mixed together byrotating a stirring stick, a stirring blade, or the like; a method inwhich the components are mixed together using a mixer, and a method inwhich the components are mixed together by applying ultrasonic wavesthereto.

The temperature and the time during the addition and mixing of therespective components are not particularly limited as long as therespective blending components do not deteriorate and may beappropriately adjusted, but the temperature is preferably 15° C. to 30°C.

<Curable Resin Film>

As described above, the curable resin film of the present invention is alayer for protecting the plurality of bumps 51 on the surface 5 a of thesemiconductor wafer 5, and the first protective film 1 a is formed byheating or curing with energy ray irradiation.

As described above, the curable resin film 1 of the present inventioncontains an epoxy-based thermosetting component having a weight-averagemolecular weight of 200 to 4,000 as the curable component, and is usedto form the first protective film 1 a by being attached to the surface 5a of the semiconductor wafer 5 having the plurality of bumps 51. Thecurable resin film 1 forms the first protective film 1 a by beingattached to the surface 5 a of the semiconductor wafer 5 having thebumps 51 with an average peak height h1 of 50 to 400 μm, an averagediameter D of 60 to 500 μm, and an average pitch P of 100 to 800 μm,heating the attached curable resin film at 100° C. to 200° C. for 0.5 to3 hours, and curing the heated curable resin film, and when longitudinalsections of the first protective film 1 a and the semiconductor wafer 5are observed by a scanning electron microscope, a ratio (h3/h1) of anaverage thickness h3 of the first protective film 1 a at a centerposition between the bumps 51 to an average peak height h1 of theplurality of bumps 51, and a ratio (h2/h1) of an average thickness h2 ofthe first protective film 1 a at a position being in contact with thebumps 51 to the average peak height h1 satisfy a relationshiprepresented by the following expression [{(h2/h1)−(h3/h1)}≤0.1].

In addition, the curable resin film 10 of the present invention iscommon to the curable resin film 1 in terms of the conditions of thedimensional relationship between the cured first protective film 1 a andthe plurality of bumps 51, but is different from the curable resin film1 from the viewpoint of containing the energy ray-curable componenthaving a weight-average molecular weight of 200 to 4,000 as thethermosetting component, and forming the first protective film 1 a bybeing cured and irradiated with energy rays under the curing conditionsof illuminance of 50 to 500 mW/cm², and light intensity of 100 to 2,000mJ/cm².

The curable resin film 1 can be formed using the thermosetting resincomposition containing a constituent material thereof. The thermosettingresin composition contains the epoxy-based thermosetting componenthaving the weight-average molecular weight of 200 to 4,000.

The physical properties such as viscoelasticity and the like of such acurable resin film 1 can be adjusted by adjusting one or both of thetype and amount of the components contained in the thermosetting resincomposition. In addition, the weight-average molecular weight of theepoxy-based thermosetting component can also be adjusted to be withinthe above range by adjusting one or both of the type and amount of thecomponent.

The thermosetting resin composition and a method of manufacturingthereof will be described in detail.

For example, among the contained components of the thermosetting resincomposition, particularly, by increasing and decreasing the amount inthe composition of the thermosetting component, physical properties suchas viscosity of the curable resin film 1 can be adjusted within thepreferable range.

Examples of a preferred curable resin film 1 include thermosetting resinlayers containing a polymer component (A) and a thermosetting component(B). The polymer component (A) is a component considered to be formed bya polymerization reaction of a polymerizable compound. In addition, thethermosetting component (B) is a component capable of a curing(polymerization) reaction using heat as a trigger of the reaction.Meanwhile, in the present invention, a polycondensation reaction is alsoconsidered as the polymerization reaction.

On the other hand, the curable resin film 10 can be formed using anenergy ray-curable resin composition containing a constituent materialthereof. The energy ray-curable resin composition contains the energyray-curable component having the weight-average molecular weight of 200to 4,000.

The physical properties such as viscoelasticity and the like of such acurable resin film 10 can be adjusted by adjusting one or both of thetype and amount of the components contained in the energy ray-curableresin composition. In addition, the weight-average molecular weight ofthe energy ray-curable component can also be adjusted to be within theabove range by adjusting one or both of the type and amount of thecomponent.

The curable resin films 1 and 10 may be a sheet made of a single layer(monolayer) or a sheet made of a plurality of layers of two or morelayers. In a case in which the curable resin films 1 and 10 is aplurality of layers, the respective layers in the plurality of layersmay be identical to or different from one another, and the combinationof the plurality of layers is not particularly limited.

In a case where the curable resin films 1 and 10 is made of theplurality of layers, all the layers constituting the curable resin films1 and 10 may satisfy the conditions of the above constituent component.

The thickness of the curable resin films 1 and 10 is not particularlylimited, and for example, is preferably 1 to 100 μm, more preferably 5to 75 μm, particularly preferably 5 to 50 μm. When the thickness of thecurable resin film 1 is equal to or more than the lower limit value, itis possible to form a first protective film 1 a having a higherprotection function.

Here, “the thickness of the curable resin film” refers to the thicknessof the entire curable resin films 1 and 10, and, for example, thethickness of the curable resin films 1 and 10 made up of a plurality oflayers refers to the total thickness of all of the layers constitutingthe curable resin films 1 and 10.

[Thermosetting Resin Composition]

The curable resin film 1 can be formed using the thermosetting resincomposition containing a constituent material thereof, that is, thethermosetting resin composition containing at least the thermosettingcomponent. For example, the curable resin film 1 can be formed at anintended portion by applying the thermosetting resin composition to atarget surface on which the curable resin film 1 is to be formed anddrying the thermosetting resin composition as necessary. The ratiobetween the amounts of components, which do not gasify at normaltemperature, in the thermosetting resin composition is, generally,identical to the ratio between the amounts of the above-describedcomponents in the curable resin film 1. Here, “normal temperature” is asdescribed above.

The thermosetting resin composition may be applied using a well-knownmethod, and examples thereof include methods in which a variety ofcoaters such as an air knife coater, a blade coater, a bar coater, agravure coater, a roll coater, a roll knife coater, a curtain coater, adie coater, a knife coater, a screen coater, a Mayer bar coater, and akiss coater are used.

The drying conditions of the thermosetting resin composition are notparticularly limited; however, in a case in which the thermosettingresin composition contains a solvent described below, the thermosettingresin composition is preferably heated and dried, and, in this case, thethermosetting resin composition is preferably dried under conditions of,for example, 70° C. to 130° C. and 10 seconds to 5 minutes.

{Thermosetting Resin Composition (III-1)}

Examples of a thermosetting resin composition include the thermosettingresin composition (III-1) (in the present embodiment, simply abbreviatedas “thermosetting resin composition (III-1)”) containing a polymercomponent (A) and a thermosetting component (B).

(Polymer Component (A))

The polymer component (A) is a polymer compound for imparting afilm-forming property, flexibility, and the like to the curable resinfilm 1.

The thermosetting resin composition (III-1) and the curable resin film 1may contain only one type or two or more types of the polymer components(A). In a case in which the polymer component (A) contains two or moretypes of the thermosetting resin composition (III-1) and the curableresin film 1, the combination and ratio thereof can be arbitrarilyselected.

Examples of the polymer component (A) include acrylic resins (resinshaving a (meth)acryloyl group), polyesters, urethane-based resins(resins having a urethane bond), acrylic urethane resins, silicone-basedresins (resin having a siloxane bond), rubber-based resins (resinshaving a rubber structure), phenoxy resins, thermosetting polyimides,and the like, and acrylic resins are preferred.

Examples of the acrylic resin in the polymer component (A) includewell-known acrylic polymers.

The weight-average molecular weight (Mw) of the acrylic resin ispreferably 10,000 to 2,000,000 and more preferably 100,000 to 1,500,000.When the weight-average molecular weight of the acrylic resin is equalto or more than the lower limit value, the shape stability (agingstability during storage) of the curable resin film 1 improves. Inaddition, when the weight-average molecular weight of the acrylic resinis equal to or less than the upper limit value, it becomes easy for thecurable resin film 1 to follow the uneven surfaces of adherends, and forexample, an effect of further suppressing the generation of voids andthe like between an adherend and the curable resin film 1 can beobtained.

The glass transition temperature (Tg) of the acrylic resin is preferably−60° C. to 70° C. and more preferably −30° C. to 50° C. When the Tg ofthe acrylic resin is equal to or higher than the lower limit value, theadhesive force between the first protective film 1 a and the firstsupporting sheet is suppressed, and thus the peeling property of thefirst supporting sheet improves. In addition, when the Tg of the acrylicresin is equal to or lower than the upper limit value, the adhesiveforce of the adherend of the curable resin film 1 and the firstprotective film 1 a improves.

Examples of the acrylic resin include polymers of one or more type of(meth)acrylic acid esters; copolymers of two or more types of monomersselected from (meth)acrylic acid, itaconic acid, vinyl acetate,acrylonitrile, styrene, N-methylol acrylamide, and the like; and thelike.

Examples of the (meth)acrylic acid esters constituting the acrylic resininclude alkyl (meth)acrylic acid esters in which an alkyl groupconstituting the alkyl ester has 1 to 18 carbon atoms and has achain-like shape such as methyl (meth)acrylate, ethyl (meth)acrylate,n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl(meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate,tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate,heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl(meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl(meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl(meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate,tetradecyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl(meth)acrylate, hexadecyl (meth)acrylate (palmityl (meth)acrylate),heptadecyl (meth)acrylate, and octadecyl (meth)acrylate (stearyl(meth)acrylate), and the like;

cycloalkyl (meth)acrylic acid esters such as isobornyl (meth)acrylateand dicyclopentanyl (meth)acrylate;

aralkyl (meth)acrylic acid esters such as benzyl (meth)acrylate;

cycloalkenyl (meth)acrylic acid esters such as dicyclopentenyl(meth)acrylate;

cycloalkenyloxy alkyl (meth)acrylic acid esters such asdicyclopentenyloxyethyl (meth)acrylate;

imide (meth)acrylate;

glycidyl group-containing (meth)acrylic acid esters such as glycidyl(meth)acrylate;

hydroxyl group-containing (meth)acrylic acid esters such ashydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate,2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate,2-hydorybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and4-hydroxybutyl (meth)acrylate; and

substituted amino group-containing (meth)acrylic acid esters such asN-methylaminoethyl (meth)acrylate; and the like. Here, “the substitutedamino group” refers to a group formed by substituting one or twohydrogen atoms in an amino group with a group other than a hydrogenatom.

The acrylic resin may be, for example, in addition to the (meth)acrylicacid ester, a resin formed by the copolymerization of one or more typesof monomers selected from (meth)acrylic acid, itaconic acid, vinylacetate, acrylonitrile, styrene, N-methylol acrylamide, and the like.

The acrylic resin may contain only one type or two or more types of themonomers. In a case in which the acrylic resin has two or more types ofmonomers, the combination and ratio thereof can be arbitrarily selected.

The acrylic resin may also have a functional group capable of bonding toother compounds such as a vinyl group, a (meth)acryloyl group, an aminogroup, a hydroxyl group, a carboxy group, or an isocyanate group. Thefunctional group in the acrylic resin may be bonded to other compoundsthrough a crosslinking agent (F) described below or may be directlybonded to other compounds without the crosslinking agent (F). When theacrylic resin is bonded to other compounds through the functional group,there is a tendency that the reliability of packages obtained using thecurable resin film 1 improves.

In the present invention, as the polymer component (A), a thermoplasticresin other than the acrylic resin (hereinafter, in some cases, simplyabbreviated as “the thermoplastic resin”) may be used singly withoutusing the acrylic resin or may be jointly used with the acrylic resin.When the thermoplastic resin is used, there are cases in which thepeeling property of the first protective film 1 a from the firstsupporting sheet 11 improves, it becomes easy for the curable resin film1 to follow the uneven surfaces of adherends, and the generation ofvoids and the like between an adherend and the curable resin film 1 isfurther suppressed.

The weight-average molecular weight of the thermoplastic resin ispreferably 1,000 to 100,000 and more preferably 3,000 to 80,000.

The glass transition temperature (Tg) of the thermoplastic resin ispreferably −30° C. to 150° C. and more preferably −20° C. to 120° C.

Examples of the thermoplastic resin include polyesters, polyurethanes,phenoxy resins, polybutene, polybutadienes, polystyrenes, and the like.

The thermosetting resin composition (III-1) and the curable resin film 1may contain only one type or two or more types of the thermoplasticresin. In a case in which the thermoplastic resin contains two or moretypes of the thermosetting resin composition (III-1) and the curableresin film 1, the combination and ratio thereof can be arbitrarilyselected.

In the thermosetting resin composition (III-1), the ratio of the amountof the polymer component (A) (that is, the amount of the polymercomponent (A) in the curable resin film 1) to the total amount of all ofthe components other than the solvent is preferably 5% to 85% by massand more preferably 5% to 80% by mass of the entire mass of thethermosetting resin composition (III-1), regardless of the type of thepolymer component (A).

There are cases in which the polymer component (A) corresponds to thethermosetting component (B). In the present invention, in a case inwhich the thermosetting resin composition (III-1) contains componentscorresponding both the polymer component (A) and the thermosettingcomponent (B) as described above, the thermosetting resin composition(III-1) is considered to contain the polymer component (A) and thethermosetting component (B).

(Thermosetting Component (B))

The thermosetting component (B) is a component for curing the curableresin film 1 so as to form a rigid first protective film 1 a.

The thermosetting resin composition (III-1) and the curable resin film 1may contain only one type or two or more types of the thermosettingcomponent (B). In a case in which the thermosetting component (B)contains two or more types of the thermosetting resin composition(III-1) and the curable resin film 1, the combination and ratio thereofcan be arbitrarily selected.

Examples of the thermosetting component (B) include epoxy-basedthermosetting resins, thermosetting polyimides, polyurethanes,unsaturated polyesters, silicone resins, and the like, and epoxy-basedthermosetting resins are preferred.

(A) Epoxy-Based Thermosetting Resin

The epoxy-based thermosetting resin is made up of an epoxy resin (B1)and a thermal curing agent (B2).

The thermosetting resin composition (III-1) and the curable resin film 1may contain only one type or two or more types of the epoxy-basedthermosetting resin. In a case in which the epoxy-based thermosettingresin contains two or more types of the thermosetting resin composition(III-1) and the curable resin film 1, the combination and ratio thereofcan be arbitrarily selected.

Epoxy Resin (B1)

As the epoxy resin (B1), well-known epoxy resins are exemplary examples.Examples thereof include polyfunctional epoxy resins, biphenylcompounds, bisphenol A diglycidyl ethers and hydrogenated substancesthereof, orthocresol novolac epoxy resins, dicyclopentadiene-type epoxyresins, biphenyl-type epoxy resins, bisphenol A-type epoxy resins,bisphenol F-type epoxy resins, phenylene skeleton-type epoxy resins, andthe like, and di- or higher-functional epoxy compounds.

As the epoxy resin (B1), an epoxy resin having an unsaturatedhydrocarbon group may also be used. The epoxy resin having anunsaturated hydrocarbon group has more favorable compatibility withacrylic resins than epoxy resins not having an unsaturated hydrocarbongroup. Therefore, when the epoxy resin having an unsaturated hydrocarbongroup is used, the reliability of packages obtained using the curableresin film improves.

Examples of the epoxy resin having an unsaturated hydrocarbon groupinclude compounds formed by converting a part of epoxy groups in apolyfunctional epoxy resin to groups having an unsaturated hydrocarbongroup. The above-described compound can be obtained by, for example, anaddition reaction of (meth)acrylic acid or a derivative thereof to anepoxy group.

In addition, examples of the epoxy resin having an unsaturatedhydrocarbon group include compounds in which a group having anunsaturated hydrocarbon group is directly bonded to an aromatic ring orthe like constituting an epoxy resin and the like.

The unsaturated hydrocarbon group is a polymerizable unsaturated group,and specific examples thereof include ethenyl groups (vinyl groups),2-propenyl group (allyl group), (meth)acryloyl groups, (meth)acrylamidegroups, and the like, and acryloyl groups are preferred.

The number-average molecular weight of the epoxy resin (B1) is notparticularly limited, but is preferably 300 to 30,000, more preferably400 to 10,000, and particularly preferably 500 to 3,000 from theviewpoint of the curing property of the curable resin film 1 and thestrength and thermal resistance of the first protective film 1 a aftercuring.

The epoxy equivalent of the epoxy resin (B1) is preferably 100 to 1,000g/eq and more preferably 300 to 800 g/eq.

One type of the epoxy resin (B1) may be used singly or two or more typesthereof may be jointly used. In a case in which two or more types of theepoxy resin (B1) are jointly used, the combination and ratio thereof canbe arbitrarily selected.

Thermal Curing Agent (B2)

The thermal curing agent (B2) functions as a curing agent of the epoxyresin (B1).

Examples of the thermal curing agent (B2) include compounds having twoor more functional groups capable of reacting with an epoxy group in onemolecule. Examples of the functional group include phenolic hydroxylgroups, alcoholic hydroxyl groups, an amino group, a carboxy group,groups in which an acid group is turned into an anhydride, and the like,phenolic hydroxyl groups, amino groups, or groups in which an acid groupis turned into an anhydride are preferred, and phenolic hydroxyl groupsor amino groups are more preferred.

As the thermal curing agent (B2), examples of phenolic curing agentshaving a phenolic hydroxyl group include polyfunctional phenolic resins,biphenol, novolac-type phenolic resins, dicyclopentadiene-based phenolicresins, aralkylphenolic resins, and the like.

As the thermal curing agent (B2), examples of amine-based curing agentshaving an amino group include dicyandiamide (hereinafter, in some cases,abbreviated as “DICY”), and the like.

The thermal curing agent (B2) may also have an unsaturated hydrocarbongroup.

Examples of the thermal curing agent (B2) having an unsaturatedhydrocarbon group include compounds formed by substituting a part ofhydroxyl groups in a phenolic resin with groups having an unsaturatedhydrocarbon group, compounds formed by directly bonding a group havingan unsaturated hydrocarbon group to an aromatic ring of a phenolicresin, and the like.

The unsaturated hydrocarbon group in the thermal curing agent (B2) isidentical to the unsaturated hydrocarbon group in the above-describedepoxy resin having an unsaturated hydrocarbon group.

In a case in which a phenolic curing agent is used as the thermal curingagent (B2), the thermal curing agent (B2) preferably has a highsoftening point or glass transition temperature since the peelingproperty from the first supporting sheet of the first protective film 1a improves.

The number-average molecular weight of the resin component such as apolyfunctional phenolic resin, a novolac-type phenolic resin, adicyclopentadiene-based phenolic resin, or an aralkylphenolic resin asthe thermal curing agent (B2) is preferably 300 to 30,000, morepreferably 400 to 10,000, and particularly preferably 500 to 3,000.

The molecular weight of a non-resin component, for example, biphenol ordicyandiamide as the thermal curing agent (B2) is not particularlylimited, and is preferably, for example, 60 to 500.

One type of the thermal curing agent (B2) may be used singly or two ormore types of the polyol compounds may be used in combination. In a casein which two or more types of the thermal curing agents (B2) are used incombination, the combination and ratio thereof can be arbitrarilyselected.

In the thermosetting resin composition (III-1) and the curable resinfilm 1, the amount of the thermal curing agent (B2) is preferably 0.1 to500 parts by mass, more preferably 1 to 200 parts by mass of the amount(100 parts by mass) of the epoxy resin (B1). When the amount of thethermal curing agent (B2) is equal to or more than the lower limitvalue, it becomes easier for the curing of the curable resin film 1 toproceed. In addition, when the amount of the thermal curing agent (B2)is equal to or less than the upper limit value, the moistureabsorptivity of the curable resin film 1 decreases, and thus thereliability of packages obtained using the curable resin film 1 furtherimproves.

In the thermosetting resin composition (III-1) and the curable resinfilm 1, the amount of the thermosetting component (B), for example, thetotal amount of the epoxy resin (B1) and the thermal curing agent (B2)is preferably 50 to 1,000 parts by mass, more preferably 100 to 900parts by mass, and particularly preferably 150 to 800 parts by mass ofthe amount (100 parts by mass) of the polymer component (A). When theamount of the thermosetting component (B) is in the above-describedrange, the adhesive force between the first protective film 1 a and thefirst supporting sheet is suppressed, and thus the peeling property ofthe first supporting sheet improves.

(Curing Accelerator (C))

The thermosetting resin composition (III-1) and the curable resin film 1may also contain a curing accelerator (C). The curing accelerator (C) isa component for adjusting the speed of curing the thermosetting resincomposition (III-1).

Examples of preferred curing accelerators (C) include tertiary aminessuch as triethylene diamine, benzyldimethylamine, triethanolamine,dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles(imidazoles in which one or more hydrogen atoms are substituted withgroups other than a hydrogen atom) such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole,2-phenyl-4,5-dihydroxymethylimidazole, and2,-phenyl-4-methyl-5-hydroxymethylimidazole; organic phosphines(phosphines in which one or more hydrogen atoms are substituted withorganic groups) such as tributyl phosphine, diphenyl phosphine, andtriphenyl phosphine; tetraphenyl boron salts such as tetraphenylphosphonium tetraphenyl borate and triphenyl phosphine tetraphenylborate; and the like.

The thermosetting resin composition (III-1) and the curable resin film 1may contain only one type or two or more types of the curing accelerator(C). In a case in which the curing accelerator (C) contains two or moretypes of the thermosetting resin composition (III-1) and the curableresin film 1, the combination and ratio thereof can be arbitrarilyselected.

In a case in which the curing accelerator (C) is used, in thethermosetting resin composition (III-1) and the curable resin film 1,the amount of the curing accelerator (C) is preferably 0.01 to 10 partsby mass and more preferably 0.1 to 5 parts by mass of the amount (100parts by mass) of the thermosetting component (B). When the amount ofthe curing accelerator (C) is equal to or more than the lower limitvalue, the effects of the use of the curing accelerator (C) can be moresignificantly obtained. When the amount of the curing accelerator (C) isequal to or less than the upper limit value, for example, an effect ofsuppressing a highly polar curing accelerator (C) migrating toward theadhesion interface with adherends in the curable resin film 1 under hightemperature and high humidity conditions and segregating becomessignificant, and the reliability of packages obtained using the curableresin film 1 further improves.

(Filler (D))

The thermosetting resin composition (III-1) and the curable resin film 1may also contain a filler (D). When curable resin film 1 contains thefiller (D), it is easy to adjust the coefficient of thermal expansion ofthe first protective film 1 a obtained by curing the curable resin film1 to be within the above range, and, when this coefficient of thermalexpansion is optimized for a subject on which the first protective film1 a is to be formed, the reliability of packages obtained using thecurable resin film further improves. In addition, when the curable resinfilm 1 contains the filler (D), it is also possible to decrease themoisture absorptivity of the first protective film 1 a or improving theheat dissipation property.

Further, in the present invention, when the curable resin film 1contains the filler (D), as described above, it is possible to obtain aneffect which can remarkably suppress the large distortion in the concaveshape on the cured first protective film 1 a.

The filler (D) may be any one of an organic filler and an inorganicfiller, but is preferably an inorganic filler.

Examples of preferred inorganic fillers include powder of silica,alumina, talc, calcium carbonate, titanium white, colcothar, siliconcarbide, boron nitride, and the like; beads obtained by spherodizingthis inorganic filler; surface-modified products of these inorganicfillers; single crystal fibers of these inorganic fillers; glass fibers;and the like.

Among these, the inorganic filler is preferably silica or alumina.

The thermosetting resin composition (III-1) and the curable resin film 1may contain only one type or two or more types of the filler (D). In acase in which the filler (D) contains two or more types of thethermosetting resin composition (III-1) and the curable resin film 1,the combination and ratio thereof can be arbitrarily selected.

In a case in which the filler (D) is used, in the thermosetting resincomposition (III-1), the ratio of the amount of the filler (D) (that is,the amount of the filler (D) in the curable resin film 1) to the totalamount of all of the components other than the solvent is preferably 5%to 80% by mass and more preferably 7% to 60% by mass. When the amount ofthe filler (D) is in the above-described range, the adjustment of thecoefficient of thermal expansion becomes easier.

In addition, when the thermosetting resin composition (III-1) and thecurable resin film 1 contain the filler (D) having an average particlediameter of 5 to 1,000 nm in the curable resin film 1 which is 5% to 80%of the entire mass of the thermosetting resin composition (III-1), it ispossible to obtain an effect which can remarkably suppress the largedistortion in the concave shape on the cured first protective film 1 a.

(Coupling Agent (E))

The thermosetting resin composition (III-1) and the curable resin film 1may also contain a coupling agent (E). When a coupling agent having afunctional group capable of reacting with an inorganic compound or anorganic compound is used as the coupling agent (E), it is possible toimprove the adhesiveness and adhesion of the curable resin film 1 toadherends. In addition, when the coupling agent (E) is used, the firstprotective film 1 a obtained by curing the curable resin film 1 is notimpaired in the thermal resistance and is improved in terms of the waterresistance.

The coupling agent (E) is preferably a compound having a functionalgroup capable of reacting with the functional group in the polymercomponent (A), the thermosetting component (B), or the like and morepreferably a silane coupling agent.

Examples of preferred silane coupling agents include3-glycidyloxypropyltrimethoxysilane,3-glycidyloxypropylmethyldiethoxysilane,3-glycidyloxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane,epoxycyclohexyl)ethyltrimethoxysilane,3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane,3-(2-aminoethylamino)propyltrimethoxysilane,3-(2-aminoethylamino)propylmethyldiethoxysilane,3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane,3-ureidopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane,3-mercaptopropylmethyldimethoxysilane,bis(3-triethoxysilylpropyl)tetrasulfane, methyltrimethoxysilane,methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane,imidazolesilane, and the like.

The thermosetting resin composition (III-1) and the curable resin film 1may contain only one type or two or more types of the coupling agent(E). In a case in which the coupling agent (E) contains two or moretypes of the thermosetting resin composition (III-1) and the curableresin film 1, the combination and ratio thereof can be arbitrarilyselected.

In a case where the coupling agent (E) is used, in the thermosettingresin composition (III-1) and the curable resin film 1, the amount ofthe coupling agent (E) is preferably 0.03 to 20 parts by mass, morepreferably 0.05 to 10 parts by mass, and particularly preferably 0.1 to5 parts by mass of the total amount (100 parts by mass of the polymercomponent (A) and the thermosetting component (B)). When the amount ofthe coupling agent (E) is equal to or more than the lower limit value,the effects of the use of the coupling agent (E) such as the improvementof the dispersibility of the filler (D) in resins and the improvement ofthe adhesiveness of the curable resin film 1 to adherends can besignificantly obtained.

In addition, when the amount of the coupling agent (E) is equal to orless than the upper limit value, the generation of outgas is furthersuppressed.

(Crosslinking Agent (F))

In a case in which a polymer component having a functional group such asa vinyl group which is capable of bonding to other compounds, a(meth)acryloyl group, an amino group, a hydroxyl group, a carboxy group,or an isocyanate group which is capable of reacting with other compoundssuch as the above-described acrylic resin is used as the polymercomponent (A), the thermosetting resin composition (III-1) and thecurable resin film 1 may also contain a crosslinking agent (F) forbonding and crosslinking the functional group to other compounds. Whenthe functional group is crosslinked to other compound using thecrosslinking agent (F), it is possible to adjust the initial adhesiveforce and the agglomerative force of the curable resin film 1.

Examples of the crosslinking agent (F) include organic polyhydricisocyanate compounds, organic polyhydric imine compounds, metalchelate-based crosslinking agents (crosslinking agents having a metalchelate structure), aziridine-based crosslinking agents (crosslinkingagents having an aziridinyl group), and the like.

Examples of the organic polyhydric isocyanate compounds include aromaticpolyhydric isocyanate compounds, aliphatic polyhydric isocyanatecompounds, and alicyclic polyhydric isocyanate compounds (hereinafter,in some cases, these compounds will be collectively abbreviated as“aromatic polyhydric isocyanate compounds and the like”); timers,isocyanurate bodies, and adduct bodies of the aromatic polyhydricisocyanate compounds and the like; terminal isocyanate urethaneprepolymers obtained by reacting the aromatic polyhydric isocyanatecompounds and the like and a polyol compound. The “adduct body” refersto a reactant of the aromatic polyhydric isocyanate compound, thealiphatic polyhydric isocyanate compound, or the alicyclic polyhydricisocyanate compound and a low-molecular-weight activehydrogen-containing compound such as ethylene glycol, propylene glycol,neopentyl glycol, trimethylolpropane, or castor oil, and examplesthereof include xylylene diisocyanate adducts of trimethylolpropane asdescribed below and the like. In addition, “the terminal isocyanateurethane prepolymer” is as described above.

More specific examples of the organic polyhydric isocyanate compoundinclude 2,4-tolylene diisocyanate; 2,6-tolylene diisocyanate;1,3-xylylene diisocyanate; 1,4-xylylene diisocyanate;diphenylmethane-4,4′-diisocyanate; diphenylmethane-2,4′-diisocyanate;3-methyldiphenylmethane diisocyanate; hexamethylene diisocyanate;isophorone diisocyanate; dicyclohexylmethane-4,4′-diisocyanate;dicyclohexylmethane-2,4′-diisocyanate; compounds obtained by adding anyone or more types of tolylene diisocyanate, hexamethylene diisocyanate,and xylylene diisocyanate to all or some of hydroxyl groups in a polyolsuch as trimethylolpropane; lysine diisocyanate; and the like.

Examples of the organic polyhydric imine compounds includeN,N′-diphenylmethane-4,4′-bis(1-aziridinecarboxamide),trimethylolpropane tri-β-aziridinylpropionate,tetramethylolmethane-tri-β-aziridinylpropionate,N,N′-toluene-2,4-bis(1-aziridinecarboxamide) triethylene melamine, andthe like.

In a case in which the organic polyhydric isocyanate compound is used asthe crosslinking agent (F), a hydroxyl group-containing polymer ispreferably used as the polymer component (A). In a case in which thecrosslinking agent (F) has an isocyanate group and the polymer component(A) has a hydroxyl group, it is possible to simply introduce acrosslinking structure into the curable resin film 1 by a reactionbetween the crosslinking agent (F) and the polymer component (A).

The thermosetting resin composition (III-1) and the curable resin film 1may contain only one type of the crosslinking agent (F). In addition,thermosetting resin composition (III-1) and the curable resin film 1 maycontain two or more types of the crosslinking agents (F), and in thiscase, the combination and ratio thereof can be arbitrarily selected.

In a case in which the crosslinking agent (F) is used, in thethermosetting resin composition (III-1), the amount of the crosslinkingagent (F) is preferably 0.01 to 20 parts by mass, more preferably 0.1 to10 parts by mass, and particularly preferably 0.5 to 5 parts by mass ofthe amount (100 parts by mass) of the polymer component (A). When theamount of the crosslinking agent (F) is equal to or more than the lowerlimit value, the effects of the use of the crosslinking agent (F) can besignificantly obtained. In addition, when the amount of the crosslinkingagent (F) is equal to or less than the upper limit value, the excess useof the crosslinking agent (F) is suppressed.

(Energy Ray-Curable Resin (G))

The thermosetting resin composition (III-1) and the curable resin film 1may contain an energy ray-curable resin (G). When the curable resin film1 contains the energy ray-curable resin (G), it is possible to changethe characteristics by being irradiated with energy rays.

The energy ray-curable resin (G) is obtained by polymerizing (curing) anenergy ray-curable compound.

Examples of the energy ray-curable compound include compounds having atleast one polymerizable double bond in the molecule, and acrylate-basedcompounds having a (meth)acryloyl group are preferred.

Examples of the acrylate-based compounds include chain-like aliphaticskeleton-containing (meth)acrylates such as trimethylolpropanetri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate,pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate,dipentaerythritol monohydroxy penta(meth)acrylate, dipentaerythritolhexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, and1,6-hexanediol di(meth)acrylate; cyclic aliphatic skeleton-containing(meth)acrylates such as dicyclopentanyl di(meth)acrylate; polyalkyleneglycol (meth)acrylates such as polyethylene glycol di(meth)acrylate;oligo ester (meth)acrylates; urethane (meth)acrylate oligomers;epoxy-modified (meth)acrylates; polyether (meth)acrylates other than theabove-described polyalkylene glycol (meth)acrylates; itaconic acidoligomers; and the like.

The weight-average molecular weight of the energy ray-curable compoundis preferably 100 to 30,000 and more preferably 300 to 10,000.

Only one type or two or more types of the energy ray-curable compoundsmay be used for polymerization. In a case in which two or more types ofthe energy ray-curable compounds are used for polymerization, thecombination and ratio thereof can be arbitrarily selected.

The thermosetting resin composition (III-1) may contain only one type ortwo or more types of the energy ray-curable resins (G). In a case inwhich the thermosetting resin composition (III-1) contains two or moretypes of the energy ray-curable resins (G), the combination and ratiothereof can be arbitrarily selected.

The amount of the energy ray-curable resin (G) in the thermosettingresin composition (III-1) is preferably 1% to 95% by mass, morepreferably 5% to 90% by mass, and particularly preferably 10% to 85% bymass, of the entire mass of the thermosetting resin composition (III-1).

(Photopolymerization Initiator (H))

In the case of containing the energy ray-curable resin (G), thethermosetting resin composition (III-1) may also contain aphotopolymerization initiator (H) in order to cause the polymerizationreaction of the energy ray curable resin (G) to more efficientlyproceed.

Examples of the photopolymerization initiator (H) include benzophenone,acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether,benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid,benzoin benzoate methyl, benzoin dimethyl ketal,2,4-diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyldiphenyl sulfide, tetramethylthiuram monosulfide,azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, 1,2-diphenylmethane,2-hydroxy-2-methyl-1-[4-(1-methylvinyl) phenyl] propanone,2,4,6-trimethylbenzoyldiphenylphosphine oxide, and2-chloroanthraquinone.

The thermosetting resin composition (III-1) may contain only one type ortwo or more types of the photopolymerization initiators (H). In a casein which the thermosetting resin composition (III-1) contains two ormore types of the photopolymerization initiators (H), the combinationand ratio thereof can be arbitrarily selected.

The amount of the photopolymerization initiators (H) in thethermosetting resin composition (III-1) is preferably 0.1 to 20 parts bymass, more preferably 1 to 10 parts by mass, and particularly preferably2 to 5 parts by mass of the amount (100 parts by mass) of the energyray-curable resin (G).

(Versatile Additive (I)) The thermosetting resin composition (III-1) andthe curable resin film 1 may also contain a versatile additive (I) aslong as the effects of the present invention are not impaired.

The versatile additive (I) may be a well-known versatile additive, canbe arbitrarily selected depending on the purpose, and is notparticularly limited, and examples of preferred versatile additivesinclude a plasticizer, an antistatic agent, an antioxidant, a colorant(a pigment or a dye), a gettering agent, and the like.

The thermosetting resin composition (III-1) and the curable resin film 1may contain only one type or two or more types of the versatile additive(I). In a case in which the thermosetting resin composition (III-1) andthe curable resin film 1 contain two or more types of the versatileadditive (I), the combination and ratio thereof can be arbitrarilyselected.

The amount of the versatile additive (I) in the thermosetting resincomposition (III-1) and the curable resin film 1 is not particularlylimited and may be appropriately selected depending on the purpose.

(Solvent) The thermosetting resin composition (III-1) preferably furthercontains a solvent. The thermosetting resin composition (III-1)containing a solvent improves in terms of the handling property.

The solvent is not particularly limited, but preferred examples thereofinclude hydrocarbons such as toluene and xylyene; alcohols such asmethanol, ethanol, 2-propanol, isobutyl alcohol (2-methyl propane-1-ol),and 1-butanol; esters such as ethyl acetate; ketones such as acetone andmethyl ethyl ketone; ethers such as tetrahydrofuran; amides (compoundshaving an amide bond) such as dimethyl formamide and N-methylpyrrolidone, and the like.

The thermosetting resin composition (III-1) may contain only one type ortwo or more types of the solvents. In a case in which the thermosettingresin composition (III-1) contains two or more types of the solvents,the combination and ratio thereof can be arbitrarily selected.

The solvent contained in the thermosetting resin composition (III-1) ispreferably methyl ethyl ketone or the like since it is possible to moreuniformly mix the components contained in the thermosetting resincomposition (III-1).

{{Method of Manufacturing Thermosetting Resin Composition}}

The thermosetting resin composition such as the thermosetting resincomposition (III-1) can be obtained by blending individual componentsfor constituting the thermosetting resin composition.

The addition order during the blending of the respective components isnot particularly limited, and two or more types of components may beadded at the same time.

In a case in which the solvent is used, the solvent may be used bymixing the solvent with all of the blending components other than thesolvent so as to dilute these blending components in advance or may beused by mixing the solvent with the blending components without dilutingall of the blending components other than the solvent in advance.

A method for mixing the respective components during blending is notparticularly limited and may be appropriately selected from well-knownmethods such as a method in which the components are mixed together byrotating a stirring stick, a stirring blade, or the like; a method inwhich the components are mixed together using a mixer, and a method inwhich the components are mixed together by applying ultrasonic wavesthereto.

The temperature and the time during the addition and mixing of therespective components are not particularly limited as long as therespective blending components do not deteriorate and may beappropriately adjusted, but the temperature is preferably 15° C. to 30°C.

[Energy Ray-Curable Resin Composition]

Hereinafter, an energy ray-curable resin composition forming the curableresin film 10 of the present invention will be described in detail. Thecurable resin film 10 can be formed using an energy ray-curable resincomposition containing a constituent material thereof. For example, thecurable resin film 1 can be formed at an intended portion by applyingthe energy ray-curable resin composition to a target surface on whichthe curable resin film 1 is to be formed and drying the curable resincomposition as necessary. The ratio between the amounts of components,which do not gasify at normal temperature, in the energy ray-curableresin composition is, generally, identical to the ratio between theamounts of the above-described components in the curable resin film.Here, “normal temperature” is as described above.

The energy ray-curable resin composition contains an energy ray-curablecomponent (a).

The energy ray-curable component (a) is preferably uncured and ispreferably pressure-sensitive adhesive and more preferably uncured andpressure-sensitive adhesive. Here, “energy rays” and “being energyray-curable” are as described above.

The curable resin film 10 formed of the energy ray-curable resincomposition may be a sheet made of a single layer (monolayer) or a sheetmade of a plurality of layers of two or more layers. In a case in whichthe curable resin film 10 formed of the energy ray-curable resincomposition is a plurality of layers, the respective layers in theplurality of layers may be identical to or different from one another,and the combination of the plurality of layers is not particularlylimited.

The thickness of the curable resin film 10 is preferably 1 to 100 μm,more preferably 5 to 75 μm, and particularly preferably 5 to 50 μm Whenthe thickness of the curable resin film 10 formed of the energyray-curable resin composition is equal to or more than the lower limitvalue, it is possible to form a first protective film 1 a having ahigher protection function. In addition, when the thickness of thecurable resin film 10 is equal to or less than the upper limit value,excessive thickness is suppressed.

Here, “the thickness of the curable resin film 10” refers to thethickness of the entire curable resin film 10 formed of the energyray-curable resin composition, and, for example, the thickness of thecurable resin film 10 made up of a plurality of layers refers to thetotal thickness of all of the layers constituting the curable resin film10.

The energy ray-curable resin composition may be applied using awell-known method, and examples thereof include methods in which avariety of coaters such as an air knife coater, a blade coater, a barcoater, a gravure coater, a roll coater, a roll knife coater, a curtaincoater, a die coater, a knife coater, a screen coater, a Mayer barcoater, and a kiss coater are used.

The drying conditions of the energy ray-curable resin composition arenot particularly limited; however, in a case in which the energyray-curable resin composition contains a solvent described below, theenergy ray-curable resin layer forming composition is preferably heatedand dried, and, in this case, the curable resin composition ispreferably dried under conditions of, for example, 70° C. to 130° C. and10 seconds to five minutes.

{{Energy Ray-Curable Resin Composition (IV-1)}}

Examples of the energy ray-curable resin composition include an energyray-curable resin composition (IV-1) containing an energy ray-curablecomponent (a).

{Energy Ray-Curable Component (a)}

The energy ray-curable component (a) is a component that is cured bybeing irradiated with energy rays and is a component for imparting afilm-forming property, flexibility, and the like to the curable resinfilm 10.

Examples of the energy ray-curable component (a) include a polymer (a1)which has an energy ray-curable group and a weight-average molecularweight of 80,000 to 2,000,000 and a compound (a2) which has an energyray-curable group and a molecular weight of 100 to 80,000. The polymer(a1) may be a polymer at least a part of which is crosslinked with acrosslinking agent or a polymer which is not crosslinked.

(Polymer Having Energy Ray-Curable Group and Weight-Average MolecularWeight of 80,000 to 2,000,000 (a1))

Examples of the polymer (a1) which has an energy ray-curable group and aweight-average molecular weight of 80,000 to 2,000,000 include anacrylic resin (a1-1) formed by polymerizing an acrylic polymer (a11)having a functional group capable of reacting with groups in othercompounds and an energy ray-curable compound (a12) having a group thatreacts with the functional group and an energy ray-curable group such asan energy ray-curable double bond.

Examples of the functional group capable of reacting with groups inother compounds include a hydroxyl group, a carboxy group, an aminogroup, a substituted amino group (a group formed by substituting one ortwo hydrogen atoms in an amino group with a group other than a hydrogenatom), an epoxy group, and the like. Here, the functional group ispreferably a group other than a carboxy group from the viewpoint ofpreventing the corrosion of circuits such as semiconductor wafers orsemiconductor chips.

Among these, the functional group is preferably a hydroxyl group.

Acrylic Polymer Having Functional Group (a11)

Examples of the acrylic polymer (a11) having the functional groupinclude acrylic polymers formed by copolymerizing an acrylic monomerhaving the above-described functional group and an acrylic monomer nothaving the above-described functional group, and the acrylic polymer maybe an acrylic polymer formed by copolymerizing the above-describedmonomers and, furthermore, a monomer other than acrylic monomers(non-acrylic monomer).

In addition, the acrylic polymer (a11) may be a random copolymer or ablock copolymer.

Examples of the acrylic monomer having the functional group includehydroxyl group-containing monomers, carboxy group-containing monomers,amino group-containing monomers, substituted amino group-containingmonomers, epoxy group-containing monomers, and the like.

Examples of the hydroxyl group-containing monomers include hydroxyalkyl(meth)acrylates such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl(meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl(meth)acrylate, and 4-hydroxybutyl (meth)acrylate; non-(meth)acrylicunsaturated alcohols such as vinyl alcohol and allyl alcohol(unsaturated alcohols not having a (meth)acryloyl skeleton); and thelike.

Examples of the carboxy group-containing monomers include ethylenicunsaturated monocarboxylic acids such as (meth)acrylic acid and crotonicacid (monocarboxylic acids having an ethylenic unsaturated bond);ethylenic unsaturated dicarboxylic acids such as fumaric acid, itaconicacid, maleic acid, and citraconic acid (dicarboxylic acids having anethylenic unsaturated bond); anhydrides of the ethylenic unsaturateddicarboxylic acid; carboxyalkyl (meth)acrylates such as 2-carboxyethylmethacrylate; and the like.

The acrylic monomer having the functional group is preferably thehydroxyl group-containing monomer or the carboxy group-containingmonomer and more preferably the hydroxyl group-containing monomer.

The acrylic polymer (a11) may be constituted of only one type or two ormore types of the acrylic monomers having the functional group. In acase in which the acrylic polymer (a11) is constituted of two or moretypes of the acrylic monomers having the functional group, thecombination and ratio thereof can be arbitrarily selected.

Examples of the acrylic monomer not having the functional group includealkyl (meth)acrylates in which an alkyl group constituting the alkylester has 1 to 18 carbon atoms and has a chain-like shape such as methyl(meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl(meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate,sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl(meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate,2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl(meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, decyl(meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl(meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate(myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl(meth)acrylate (palmityl (meth)acrylate), heptadecyl (meth)acrylate, andoctadecyl (meth)acrylate (stearyl (meth)acrylate) and the like.

In addition, examples of the acrylic monomer not having the functionalgroup also include alkoxyalkyl group-containing (meth)acrylic acidesters such as methoxymethyl (meth)acrylate, methoxyethyl(meth)acrylate, ethoxymethyl (meth)acrylate, and ethoxyethyl(meth)acrylate; (meth)acrylic acid esters having an aromatic group whichincludes (meth)acrylic acid aryl ester such as phenyl (meth)acrylate orthe like; non-crosslinkable (meth)acrylamides and derivatives thereof;(meth)acrylic acid esters having a non-crosslinkable tertiary aminogroup such as N,N-dimethyl aminoethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate; and the like.

The acrylic polymer (a11) may be constituted of only one type or two ormore types of the acrylic monomers not having the functional group. In acase in which the acrylic polymer (a11) is constituted of two or moretypes of the acrylic monomers not having the functional group, thecombination and ratio thereof can be arbitrarily selected.

Examples of the non-acrylic monomer include olefins such as ethylene andnorbornene; vinyl acetate; styrene; and the like.

The acrylic polymer (a11) may be constituted of only one type or two ormore types of the non-acrylic monomers. In a case in which the acrylicpolymer (a11) is constituted of two or more types of the non-acrylicmonomers, the combination and ratio thereof can be arbitrarily selected.

The ratio (amount of a constituent unit derived from the acrylic monomerhaving the functional group to the entire mass of constituent unitsconstituting the acrylic polymer (a11) is preferably 0.1% to 50% bymass, more preferably 1% to 40% by mass, and particularly preferably 3%to 30% by mass. When the ratio is in the above-described range, in theacrylic resin (a1-1) obtained by polymerization between the acrylicpolymer (a11) and the energy ray-curable compound (a12), it becomespossible to easily adjust the degree of curing of the first protectivefilm to a preferred range with the amount of the energy ray-curablegroup.

The acrylic polymer (a11) may be constituted of only one type or two ormore types of the acrylic resins (a1-1). In a case in which the acrylicpolymer (a11) is constituted of two or more types of the acrylic resins(a1-1), the combination and ratio thereof can be arbitrarily selected.

In the energy ray-curable energy ray-curable resin composition (IV-1),the amount of the acrylic resin (a1-1) is preferably 1% to 60% by mass,more preferably 3% to 50% by mass, and particularly preferably 5% to 40%by mass of the entire mass of the energy ray-curable resin composition(IV-1).

Energy Ray-Curable Compound (a12)

The energy ray-curable compound (a12) is preferably an energyray-curable compound having one or more types of groups selected fromthe group consisting of an isocyanate group, an epoxy group, and acarboxy group as the group capable of reacting with the functional groupin the acrylic polymer (a11) and more preferably an energy ray-curablecompound having an isocyanate group as the above-described group. Forexample, in a case in which the energy ray-curable compound (a12) has anisocyanate group as the above-described group, this isocyanate groupeasily reacts with a hydroxyl group in the acrylic polymer (a11) havingthe hydroxyl group as the functional group.

The number of the energy ray-curable groups in one molecule of theenergy ray-curable compound (a12) is preferably 1 to 5 and morepreferably 1 or 2.

Examples of the energy ray-curable compound (a12) include2-methacryloyloxyethyl isocyanate, methaisopropenyl-α,α-dimethylbenzylisocyanate, methacryloyl isocyanate, ally isocyanate,1,1-(bisacryloyloxymethyl)ethyl isocyanate;

acryloyl monoisocyanate compounds obtained by a reaction between adiisocyante compound or a polyisocyanate compound and hydroxyethyl(meth)acrylate; and

acryloyl monoisocyanate compounds obtained from a reaction among adiisocyante compound or a polyisocyanate compound, a polyol compound,and hydroxyethyl (meth)acrylate; and the like.

Among these, the energy ray-curable compound (a12) is preferably2-methacryloyloxyethyl isocyanate.

The energy ray-curable compound (a12) may be constituted of only onetype or two or more types of the acrylic resins (a1-1). In a case inwhich the energy ray-curable compound (a12) is constituted of two ormore types of the acrylic resins (a1-1), the combination and ratiothereof can be arbitrarily selected.

The ratio of the amount of an energy ray-curable group derived from theenergy ray-curable compound (a12) to the amount of the functional groupderived from the acrylic polymer (a11) in the acrylic resin (a1-1) ispreferably 20 to 120 mol %, more preferably 35 to 100 mol %, andparticularly preferably 50 to 100 mol %. When the ratio of the amount isin the above-described range, the adhesive force of the first protectivefilm after curing becomes stronger. Meanwhile, in a case in which theenergy ray-curable compound (a12) is a monofunctional compound (havingone group in one molecule), the upper limit value of the ratio of theamount becomes 100 mol %; however, in a case in which the energyray-curable compound (a12) is a polyfunctional compound (having two ormore groups in one molecule), the upper limit value of the ratio of theamount exceeds 100 mol % in some cases.

The weight-average molecular weight (Mw) of the polymer (a1) ispreferably 100,000 to 2,000,000 and more preferably 300,000 to1,500,000.

Here, “the weight-average molecular weight” is as described above.

In a case in which at least a part of the polymer (a1) is crosslinkedwith a crosslinking agent, the polymer (a1) may be a polymer that isformed by polymerizing monomers which do not correspond to any of themonomers described above as the monomers constituting the acrylicpolymer (a11) and have a group that reacts with the crosslinking agentand is crosslinked in the group that reacts with the crosslinking agentor may be a polymer crosslinked in a group which is derived from theenergy ray-curable compound (a12) and reacts with the functional group.

The energy ray-curable resin composition (IV-1) and the curable resinfilm 10 may contain only one type or two or more types of the polymers(a1). In a case in which the energy ray-curable resin composition (IV-1)and the curable resin film 10 contain two or more types of the polymers(a1), the combination and ratio thereof can be arbitrarily selected.

(Compound Having Energy Ray-Curable Group and Weight-Average MolecularWeight of 100 to 80,000 (a2))

Examples of the energy ray-curable group having the compound (a2) whichhas an energy ray-curable group and a weight-average molecular weight of100 to 80,000 include groups having an energy ray-curable double bond,and preferred examples thereof include a (meth)acryloyl group, a vinylgroup, and the like.

The compound (a2) is not particularly limited as long as the compoundsatisfies the above-described conditions, and examples thereof includelow-molecular-weight compounds having an energy ray-curable group, epoxyresins having an energy ray-curable group, phenolic resins having anenergy ray-curable group, and the like.

Among the compound (a2), examples of the low-molecular-weight compoundshaving an energy ray-curable group include polyfunctional monomers,oligomers, and the like, and acrylate-based compounds having a(meth)acryloyl group are preferred.

Examples of the acrylate compounds include difunctional (meth)acrylatessuch as 2-hydroxy-3-(meth)acryloyloxypropoyl methacrylate, polyethyleneglycol di(meth)acrylate, propoxylated ethoxylated bisphenol Adi(meth)acrylate, 2,2-bis[4-((meth)acryloxypolyethoxy)phenyl]propane,ethoxylated bisphenol A di(meth)acrylate,2,2-bis[4-((meth)acryloxydiethoxy)phenyl]propane,9,9-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]fluorene,2,2-bis[4-((meth)acryloxypolypropoxy)phenyl]propane,tricyclodecanedimethanol di(meth)acrylate, 1,10-decanedioldi(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanedioldi(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropyleneglycol di(meth)acrylate, polypropylene glycol di(meth)acrylate,polytetramethylene glycol di(meth)acrylate, ethylene glycoldi(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycoldi(meth)acrylate, 2,2-bis[4-((meth)acryloylethoxy)phenyl]propane,neopentyl glycol di(meth)acrylate, ethoxylated polypropylene glycoldi(meth)acrylate, and 2-hydroxy-1,3-di(meth)acryloxypropane;

polyfunctional (meth)acrylates such as tris(2-(meth)acryloxyethyl)isocyanurate, ε-caprolacton-modified tris-(2-(meth)acryloxyethyl)isocyanurate, ethoxylated glycerin tri(meth)acrylate, pentaerythritoltri(meth)acrylate, trimethylolpropane tri(meth)acrylate,ditrimethylolpropane tetra(meth)acrylate, ethoxylated pentaerythritoltetra(meth)acrylate, pentaerythritol tetra(meth)acrylate,dipentaerythritol poly(meth)acrylate, and dipentaerythritolhexa(meth)acrylate;

polyfunctional (meth)acrylate oligomers such as urethane (meth)acrylateoligomers; and the like.

Among the compound (a2), as the epoxy resins having an energyray-curable group, the phenolic resins having an energy ray-curablegroup, for example, the epoxy resins described in Paragraph 0043 and thelike of “Japanese Unexamined Patent Application, First Publication No.2013-194102” can be used. These resins also correspond to resinsconstituting a thermosetting component described below; however, in thepresent invention, the resins will be handled as the compound (a2).

The weight-average molecular weight of the compound (a2) is preferably100 to 30,000 and more preferably 300 to 10,000.

The energy ray-curable resin composition (IV-1) and the curable resinfilm 10 may contain only one type or two or more types of the compounds(a2). In a case in which the energy ray-curable resin composition (IV-1)and the curable resin film 10 contain two or more types of the compounds(a2), the combination and ratio thereof can be arbitrarily selected.

{Polymer not Having Energy Ray-Curable Group (b)}

In the case where the energy ray-curable resin composition (IV-1) andthe curable resin film 10 contain the compound (a2) as the energyray-curable component (a), the energy ray-curable resin composition(IV-1) and the energy ray-curable resin layer preferably further containa polymer (b) not having any energy ray-curable groups.

The polymer (b) may be a polymer at least a part of which is crosslinkedwith a crosslinking agent or a polymer which is not crosslinked.

Examples of the polymer (b) not having any energy ray-curable groupinclude acrylic polymers, phenoxy resins, urethane resins, polyesters,rubber-based resins, acrylic urethane resins, and the like.

Among these, the polymer (b) is preferably an acrylic polymer(hereinafter, in some cases, abbreviated as “the acrylic polymer(b-1)”).

The acrylic polymer (b-1) may be a well-known acrylic polymer, and, forexample, the acrylic polymer may be a homopolymer of one type of acrylicmonomer, a copolymer of two or more types of acrylic monomers. Inaddition, the acrylic polymer (b-1) may be a copolymer of one or moretypes of acrylic monomers and one or more types of monomers other thanacrylic monomers (non-acrylic monomers).

Examples of the acrylic monomer constituting the acrylic polymer (b-1)include alkyl (meth)acrylates, (meth)acrylic acid ester having a cyclicskeleton, glycidyl group-containing (meth)acrylic acid ester, hydroxylgroup-containing (meth)acrylic acid esters, and substituted aminogroup-containing (meth)acrylic acid esters. Here, “substituted aminogroup” is as described above.

Examples of the alkyl (meth)acrylates include alkyl (meth)acrylates inwhich an alkyl group constituting the alkyl ester has 1 to 18 carbonatoms and has a chain-like shape such as methyl (meth)acrylate, ethyl(meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate,n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl(meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl(meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate,isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate,isononyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate,dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate,tetradecyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl(meth)acrylate, hexadecyl (meth)acrylate (palmityl (meth)acrylate),heptadecyl (meth)acrylate, and octadecyl (meth)acrylate (stearyl(meth)acrylate) and the like.

Examples of the (meth)acrylic acid esters having a cyclic skeletoninclude cycloalkyl (meth)acrylic acid esters such as isobornyl(meth)acrylate and dicyclopentanyl (meth)acrylate;

aralkyl (meth)acrylic acid esters such as benzyl (meth)acrylate;

cycloalkenyl (meth) acrylic acid esters such as dicyclopentenyl (meth)acrylic acid esters;

cycloalkenyloxy alkyl (meth) acrylic acid esters such asdicyclopentenyloxyethyl (meth) acrylic acid esters; and the like.

Examples of the glycidyl group-containing (meth)acrylic acid estersinclude glycidyl (meth)acrylate and the like.

Examples of the hydroxyl group-containing (meth)acrylic acid estersinclude hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate,2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate,2-hydorybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate,4-hydroxybutyl (meth)acrylate, and the like.

Examples of the substituted amino group-containing (meth)acrylic acidesters include N-methylaminoethyl (meth)acrylate and the like.

Examples of the non-acrylic monomer constituting the acrylic polymer(b-1) include olefins such as ethylene and norbornene; vinyl acetate;styrene; and the like.

Examples of the polymer (b) at least a part of which is crosslinked witha crosslinking agent and which does not have the energy ray-curablegroup include polymers in which a reactive functional group in thepolymer (b) reacts with a crosslinking agent.

The reactive functional group may be appropriately selected depending onthe type and the like of the crosslinking agent and is not particularlylimited. For example, in a case in which the crosslinking agent is apolyisocyanate compound, examples of the reactive functional groupinclude a hydroxyl group, a carboxy group, an amino group, and the like,and, among these, the hydroxyl group that is highly reactive withisocyanate groups is preferred. In addition, in a case in which thecrosslinking agent is an epoxy-based compound, examples of the reactivefunctional group include a carboxy group, an amino group, an amidegroup, and the like, and, among these, the carboxy group that is highlyreactive with epoxy groups is preferred. Here, the reactive functionalgroup is preferably a group other than a carboxy group from theviewpoint of preventing the corrosion of circuits such as semiconductorwafers or semiconductor chips.

Examples of the polymer (b) which has the reactive functional group butdoes not have any energy ray-curable groups include polymers obtained bypolymerizing monomers having at least the reactive functional group. Inthe case of the acrylic polymer (b-1), as any one or both of the acrylicmonomer and the non-acrylic monomer that have been exemplified as themonomers constituting the acrylic polymer, monomers having the reactivefunctional group may be used. For example, examples of the polymer (b)having a hydroxyl group as the reactive functional group includepolymers obtained by polymerizing hydroxyl group-containing(meth)acrylic acid ester and also include polymers obtained bypolymerizing monomers formed by substituting one or more hydrogen atomsin the previously exemplary examples of an acrylic monomer ornon-acrylic monomer with the reactive functional group.

In the polymer (b) having the reactive functional group, the ratio(amount) of the amount of a constituent unit derived from a monomerhaving the reactive functional group is preferably 1 to 20% by mass andmore preferably 2 to 10% by mass of the entire mass of constituent unitsconstituting the polymer. When the ratio is in the above-describedrange, in the polymer (b), the degree of crosslinking is in a morepreferred range.

The weight-average molecular weight (Mw) of the polymer (b) not havingany energy ray-curable groups is preferably 10,000 to 2,000,000 and morepreferably 100,000 to 1,500,000 since the film-forming property of theenergy ray curable resin composition (IV-1) becomes more preferable.

Here, “the weight-average molecular weight” is as described above.

The energy ray curable resin composition (IV-1) energy ray-curable resincomposition (IV-1) and the curable resin film 10 may contain only onetype or two or more types of the polymers (b) not having any energyray-curable groups. In a case in which the energy ray curable resincomposition (IV-1) and the curable resin film 10 contain two or moretypes of the polymers (b) not having any energy ray-curable groups, thecombination and ratio thereof can be arbitrarily selected.

Examples of the energy ray-curable resin composition (IV-1) includecompositions containing any one or both of the polymer (a1) and thecompound (a2). In the case of containing the compound (a2), the energyray-curable resin composition (IV-1) preferably further contains apolymer (b) not having an energy ray-curable group, and in this case,the polymer (a1) is further preferably contained. In addition, theenergy ray-curable resin composition (IV-1) may contain the polymer (a1)and the polymer (b) not having any energy ray-curable groups withoutcontaining the compound (a2).

In a case where the energy ray-curable resin composition (IV-1) containsthe polymer (a1), the compound (a2), and the polymer (b) not having anyenergy ray-curable groups, in the energy ray-curable resin composition(IV-1), the amount of the compound (a2) is preferably 10 to 400 parts bymass, and more preferably 30 to 350 parts by mass of the total amount(100 parts by mass) of the polymer (a1) and the polymer (b) not havingany energy ray-curable groups.

In the energy ray-curable resin composition (IV-1), the ratio of thetotal amount of the energy ray-curable component (a) and the polymer (b)not having any energy ray-curable groups (that is, the total amount ofthe energy ray-curable component (a) and the polymer (b) not having anyenergy ray-curable groups in the curable resin film 10) to the totalamount of the components other than the solvent is preferably 5% to 90%by mass, more preferably 10% to 80% by mass, and particularly preferably20% to 70% by mass. When the ratio of the amount of the energyray-curable component is in the above-described range, the energyray-curing property of the curable resin film 10 becomes more favorable.

The energy ray-curable resin composition (IV-1) may also contain, inaddition to the energy ray-curable component, one or more types ofelements selected from the group consisting of a thermosettingcomponent, a photopolymerization initiator, a filler, a coupling agent,a crosslinking agent, and a versatile additive depending on the purpose.For example, when the energy ray-curable resin composition (IV-1)containing the energy ray-curable component and a thermosettingcomponent is used, the adhesive force of the curable resin film 10 to beformed to adherends improves by heating, and the strength of the firstprotective film 1 a formed of this curable resin film 10 also improves.

As the thermosetting component, the photopolymerization initiator, thefiller, the coupling agent, the crosslinking agent, and the versatileadditive in the energy ray-curable resin composition (IV-1), it ispossible to exemplify those which are the same as the thermosettingcomponent (B), the photopolymerization initiator (H), the filler (D),the coupling agent (E), the crosslinking agent (F), and the versatileadditive (I) in the energy ray-curable resin composition (III-1).

In the energy ray-curable resin composition (IV-1), one type of each ofthe thermosetting component, the photopolymerization initiator, thefiller, the coupling agent, the crosslinking agent, and the versatileadditive may be used singly or two or more types thereof may be jointlyused, and, in a case in which two or more types thereof are used, thecombination and ratio thereof can be arbitrarily selected.

The amounts of the thermosetting component, the photopolymerizationinitiator, the filler, the coupling agent, the crosslinking agent, andthe versatile additive in the energy ray-curable resin composition(IV-1) may be appropriately adjusted depending on the purpose and arenot particularly limited.

From the viewpoint that the handling property of the energy ray-curableresin composition (IV-1) improves by dilution, it is preferable that theenergy ray-curable resin composition (IV-1) further contains a solvent.

Examples of the solvent contained in the energy ray-curable resincomposition (IV-1) include the same solvent as that in the energyray-curable resin composition (III-1).

The energy ray-curable resin composition (IV-1) may contain only onetype or two or more types of the solvents.

{{Other Components}}

In the energy ray-curable resin composition used for the curable resinfilm 10 of the present invention, in addition to the above-describedenergy ray-curable component, similar to the case of the curable resinfilm 1 containing the thermosetting component described above, thecomponents other than the curable component, that is, an appropriateamount of a curing accelerator (C), a filler (D), a coupling agent (E)and the like can be contained.

In addition, even in the curable resin film 10 formed of the energyray-curable resin composition, the same action as that of the curableresin film 1 can be obtained by containing components other than theabove-described energy ray-curable component.

{{Method of Manufacturing of Energy Ray-Curable Resin Composition}}

The energy ray-curable resin composition such as energy ray-curableresin composition (IV-1) can be obtained by blending individualcomponents for constituting the first interlayer forming composition.

The addition order during the blending of the respective components isnot particularly limited, and two or more types of components may beadded at the same time.

In a case in which the solvent is used, the solvent may be used bymixing the solvent with all of the blending components other than thesolvent so as to dilute these blending components in advance or may beused by mixing the solvent with the blending components without dilutingall of the blending components other than the solvent in advance.

A method for mixing the respective components during blending is notparticularly limited and may be appropriately selected from well-knownmethods such as a method in which the components are mixed together byrotating a stirring stick, a stirring blade, or the like; a method inwhich the components are mixed together using a mixer, and a method inwhich the components are mixed together by applying ultrasonic wavesthereto.

The temperature and the time during the addition and mixing of therespective components are not particularly limited as long as therespective blending components do not deteriorate and may beappropriately adjusted, but the temperature is preferably 15° C. to 30°C.

<<Method for Manufacturing First Protective Film Forming Sheet>>

The first protective film forming sheets 1A and 10A can be manufacturedby sequentially stacking the respective layers described above so as toobtain the corresponding positional relationship. The methods forforming the respective layers are as described above.

For example, in the manufacturing of the first supporting sheet 11, in acase in which the first pressure-sensitive adhesive layer or the firstinterlayer is stacked on the first base material, the firstpressure-sensitive adhesive layer or the first interlayer can be stackedby applying the first pressure-sensitive adhesive composition or thefirst interlayer forming composition described above onto the first basematerial and drying the composition or irradiating the composition withenergy rays as necessary.

Meanwhile, for example, in a case in which the curable resin film isfurther stacked on the first pressure-sensitive adhesive layer that hasbeen stacked on the first base material, the curable resin film can bedirectly formed by applying the thermosetting resin composition or theenergy ray-curable protective film forming composition on the firstpressure-sensitive adhesive layer. Similarly, in a case in which thefirst pressure-sensitive adhesive layer is further stacked on the firstinterlayer that has been stacked on the first base material, the firstpressure-sensitive adhesive layer can be directly formed by applying thefirst pressure-sensitive adhesive composition onto the first interlayer.As described above, in a case in which a stacking structure of twocontinuous layers is formed using any compositions, it is possible tonewly form a layer by further applying the composition onto a layerformed of the above-described composition. Here, the stacking structureof two continuous layers is preferably formed by forming, between thesetwo layers, the layer which is stacked from the back on a separatepeeling film in advance using the above-described composition andattaching the exposed surface opposite to the surface of thealready-formed layer in contact with the peeling film to the exposedsurface of the other layer that has been formed. At this time, theabove-described composition is preferably applied onto a peeling-treatedsurface of the peeling film. The peeling film may be removed asnecessary after the formation of the stacking structure.

For example, in a case in which the first protective film forming sheets(the first protective film forming sheet in which the first supportingsheet 11 is a stacked substance of the first base material and the firstpressure-sensitive adhesive layer) 1A and 10A formed by stacking thefirst pressure-sensitive adhesive layer on the first base material andstacking the curable resin layer on the first pressure-sensitiveadhesive layer are manufactured, first, the first pressure-sensitiveadhesive composition is applied onto the first base material and theapplied first base material is dried as necessary or being irradiatedwith energy rays so as to stack the first pressure-sensitive adhesivelayer on the first base material in advance. In addition, the firstprotective film forming sheets 1A and 10A can be obtained by,separately, applying the thermosetting resin composition or the energyray-curable protective film forming composition onto the peeling filmand drying the applied peeling film as necessary so as to form thecurable resin film 1 containing thermosetting components on the peelingfilm, and attaching the exposed surface of the curable resin film 1 tothe exposed surface of the first pressure-sensitive adhesive layer thathas been stacked on the first base material so as to stack the curableresin films 1 and 10 on the first pressure-sensitive adhesive layer.

Further, for example, in a case where the first supporting sheet 11 ismanufactured by stacking the first interlayer on the first basematerial, and stacking the first pressure-sensitive adhesive layer onthe first interlayer, first, the first interlayer forming composition isapplied on the first base material, and dried as necessary so as tostack the first interlayer on the first base material. In addition,separately, the first supporting sheet 11 can be obtained by applyingthe first pressure-sensitive adhesive composition onto the peeling film,drying or irradiating the first pressure-sensitive adhesive compositionwith energy rays as necessary so that the first pressure-sensitiveadhesive layer is formed on the peeling film, and then attaching theexposed surface of the first pressure-sensitive adhesive layer to theexposed surface of the first interlayer that has been stacked on thefirst base material so as to stack the first pressure-sensitive adhesivelayer on the first interlayer. In this case, the first protective filmforming sheets 1A and 10A can be obtained by, for example, separately,further applying the thermosetting resin composition or the energyray-curable protective film forming composition onto the peeling filmand drying the thermosetting resin composition or the energy ray-curableprotective film forming composition as necessary so as to form thecurable resin film 1 containing the thermosetting component on thepeeling film and attaching the exposed surface of the curable resinlayer to the exposed surface of the first pressure-sensitive adhesivelayer that has been stacked on the first interlayer so as to stack thecurable resin films 1 and 10 on the first pressure-sensitive adhesivelayer.

Meanwhile, in a case in which the first pressure-sensitive adhesivelayer or the first interlayer is stacked on the first base material, asdescribed above, the first pressure-sensitive adhesive layer or thefirst interlayer may be stacked on the first base material by, insteadof applying the first pressure-sensitive adhesive composition or thefirst interlayer forming composition onto the first base material,applying the first pressure-sensitive adhesive composition or the firstinterlayer forming composition onto the peeling film and drying thecomposition as necessary so as to form the first pressure-sensitiveadhesive layer or the first interlayer on the peeling film and attachingthe exposed surface of this layer to one surface of the first basematerial so as to stack the first pressure-sensitive adhesive layer orthe first interlayer on the first base material.

In any of the methods, the peeling film may be removed at an arbitrarytiming after the formation of the intended stacking structure.

As described above, all of the layers other than the first base materialwhich constitute the first protective film forming sheets 1A and 10A canbe stacked using a method in which the layers are formed on the peelingfilm in advance and attached on a surface of an intended layer, and thusthe first protective film forming sheets 1A and 10A may be manufacturedby appropriately selecting layers for which the above-described stepsare employed as necessary.

Meanwhile, the first protective film forming sheets 1A and 10A is,generally, stored in a state in which the peeling film is attached tothe surface of the outermost layer (for example, the curable resin films1 and 10) on the opposite side to the first supporting sheet 11.Therefore, the first protective film forming sheets 1A and 10A can alsobe obtained by applying a composition for forming a layer constitutingthe outermost layer such as thermosetting resin composition or theenergy ray-curable protective film forming composition onto the peelingfilm (preferably the peeling-treated surface thereof) and drying theapplied peeling film as necessary so as to form the layer constitutingthe outermost layer on the peeling film, stacking the remaining layerson the exposed surface on the opposite side to the surface of the layerin contact with the peeling film using any of the above-describedmethods, and leaving the layers in the attached state without removingthe peeling film.

<<Action and Effect>>

As described above, according to the present invention, the curableresin film and the first protective film forming sheet provided with thecurable resin film, after optimizing the weight-average molecular weightof the curable component contained in the curable resin film used in forforming the first protective film, when a dimensional relationshipbetween of the first protective film cured under predeterminedconditions and the plurality of bumps on a semiconductor wafer having aplurality of bumps of a predetermined dimensional shape and arrangementcondition, and thereby the occurrence of the large distortion in theconcave shape on the first protective film disposed between the bumpscan be suppressed are appropriately defined.

With this, for example, the inspection in a step of manufacturing asemiconductor wafer and the alignment accuracy in a step of dicing thesemiconductor wafer into a chip improve.

Therefore, the inspection accuracy and the dicing accuracy in themanufacturing step improve, and a semiconductor package excellent in thereliability can be manufactured.

EXAMPLES

Next, the present invention will be described in more detail bydescribing examples and comparative examples.

The scope of the present invention is not limited to the examples, andthe curable resin film and the first protective film forming sheetaccording to the present invention can be performed by appropriatelychanging and modifying within the range without changing the gist of thepresent invention.

The components used for manufacturing the thermosetting resincomposition are indicated below.

Polymer Component

Polymer component (A)-1: An acrylic resin (having a weight-averagemolecular weight of 800,000 and a glass transition temperature of −28°C.) obtained by copolymerizing butyl acrylate (hereinafter, abbreviatedas “BA”) (55 parts by mass), methyl acrylate (hereinafter, abbreviatedas “MA”) (10 parts by mass), glycidyl methacrylate (hereinafter,abbreviated as “GMA”) (20 parts by mass), and 2-hydroxyethyl acrylate(hereinafter, abbreviated as “HEA”) (15 parts by mass). The mixing ratioof the respective components are indicated in the following Table 1.

Epoxy Resin

Epoxy resin (B1)-1: A liquid bisphenol F type epoxy resin (“YL 983 U”manufactured by Mitsubishi Chemical Corporation); weight-averagemolecular weight=340

Epoxy resin (B1)-2: A polyfunctional aromatic type epoxy resin(“EPPN-502H” manufactured by Nippon Kayaku Co., Ltd.); weight-averagemolecular weight=1,000

Epoxy resin (B1)-3: A dicyclopentadiene type epoxy resin (“EPICLONHP-7200” manufactured by DIC Corporation); weight-average molecularweight=600

Thermal Curing Agent

Thermal curing agent (B2)-1: A novolac-type phenolic resin (“BRG-556”manufactured by Showa Denko KK)

Curing Accelerator

Curing accelerator (C)-1: 2-phenyl-4,5-dihydroxymethylimidazole(“Curezol 2 PHZ-PW” manufactured by Shikoku Chemicals Corporation)

Filler

Filler (D)-1: A spherical silica modified with an epoxy group (“AdmananoYA 050 C-MKK” manufactured by Admatechs); 0.05 μm (average particlediameter); 19% by mass (content ratio in thermosetting resincomposition)

Example 1

<Manufacturing of First Protective Film Forming Sheet (Curable ResinFilm)>

(Manufacturing of Thermosetting Resin Composition)

The polymer component (A)-1, the epoxy resin (B1)-1, the epoxy resin(B1)-2, the epoxy resin (B1)-3, the thermal curing agent (B2)-1, thecuring accelerator (C)-1, and the filler (D)-1 were dissolved anddispersed in methyl ethyl ketone such that the ratio of the amount tothe total amount of all components other than the solvent is the valueindicated in the following Table 1 (described as “content ratio” inTable 1), and stirred at 23° C. so as to obtain a thermosetting resincomposition (III-1) having a solid content concentration of 55% by massas a thermosetting resin composition.

(Manufacturing of Pressure-Sensitive Adhesive Resin (I-2a))

2-ethylhexyl acrylate (hereinafter, abbreviated as “2EHA”) (80 parts bymass) and HEA (20 parts by mass) were set as raw materials of acopolymer, and then a polymerization reaction was performed so as toobtain an acrylic polymer.

2-methacryloyloxyethyl isocyanate (hereinafter, abbreviated as “MOI”)(22 parts by mass, approximately 80 mol % to HEA) was added to theacrylic polymer, and an addition reaction was performed at 50° C. for 48hours in an air stream so as to obtain a target pressure-sensitiveadhesive resin (I-2a).

(Manufacturing of First Pressure-Sensitive Adhesive Composition)

As an isocyanate crosslinking agent, a tolylene diisocyanate trimeradduct of trimethylolpropane was added to the pressure-sensitiveadhesive resin (I-2a) (100 parts by mass) obtained above, (“Coronate L”manufactured by Tosoh Corporation) (0.5 parts by mass) and stirred at23° C. so as to obtain a first pressure-sensitive adhesive composition(I-2) having a solid content concentration of 30% by mass, as the firstpressure-sensitive adhesive composition. Note that, the number ofcompounding parts in this “Manufacturing of First Pressure-SensitiveAdhesive Composition” is all in terms of solid content.

(Manufacturing of First Protective Film Forming Sheet)

The above-obtained first pressure-sensitive adhesive composition wasapplied onto a peeling-treated surface of a peeling film (“SP-PET381031”manufactured by Lintec Corporation, thickness: 38 μm) obtained bycarrying out a peeling treatment on a single surface of a polyethyleneterephthalate film with a silicone treatment and was heated and dried at120° C. for 2 minutes, thereby forming a 100 μm-thick firstpressure-sensitive adhesive layer.

Next, a 105 μm-thick stacked film formed by stacking a polyolefin film(thickness: 25 μm), an adhesive layer (thickness: 2.5 μm), apolyethylene terephthalate film (thickness: 50 μm), an adhesive layer(thickness: 2.5 μm), and a polyolefin film (thickness: 25 μm) in thisorder was attached as a first base material to an exposed surface of thefirst pressure-sensitive adhesive layer in one pressure-sensitiveadhesive sheet, thereby obtaining a first supporting sheet.

The above-obtained thermosetting resin composition was applied onto apeeling-treated surface of a peeling film (“SP-PET381031” manufacturedby Lintec Corporation, thickness: 38 μm) obtained by carrying out apeeling treatment on a single surface of a polyethylene terephthalatefilm with a silicone treatment and was dried at 100° C. for 2 minute,thereby forming a 40 μm-thick thermosetting curable resin film.

Next, the peeling film was removed from the first pressure-sensitiveadhesive layer of the above-obtained first supporting sheet, an exposedsurface of the curable resin film obtained above was attached to anexposed surface of the first pressure-sensitive adhesive layer, therebyobtaining the first protective film forming sheet formed by stacking thefirst base material, the first pressure-sensitive adhesive layer, thecurable resin film, and the peeling film in this order in the thicknessdirection.

<Evaluation of Semiconductor Wafer after Forming Protective Film>

(Confirmation of Distortion after Curing Curable Resin Film to FormProtective Film)

The first protective film is formed on the bump-formed surface of thesemiconductor wafer by using the curable resin film (the firstprotective film forming sheet) obtained above description.

That is, first, the back surface protective film was attached to theback surface side of the semiconductor wafer provided with the pluralityof bumps on the surface, the first protective film forming sheet wasattached to the surface side, and the back surface protective film, thesemiconductor wafer, and the first protective film forming sheet(curable resin film) were sequentially stacked so as to manufacture astacked body.

Next, the first pressure-sensitive adhesive layer was exposed by peelingthe first supporting sheet from the back surface protective sheet, andthe first supporting sheet was attached to an upper surface of a ringframe for wafer dicing such that a stacked body (semiconductor wafer)was fixed and the first supporting sheet was peeled from the firstprotective film forming sheet.

Subsequently, while applying a pressure of 0.5 MPa to the curable resinfilm on the semiconductor wafer fixed to the ring frame for waferdicing, using a pressure and thermal curing apparatus (“RAD-9100”manufactured by Lintec Corporation), the curable resin film was heatedat a set temperature of 180° C. for one hour so as to be softened andthen cured so as to form the first protective film.

In addition, when the longitudinal section of the semiconductor waferafter forming the protective film was observed by the scanning electronmicroscope, and as shown in FIGS. 1A and 1B, the average peak height h1of the plurality of bumps, the average thickness h2 of the firstprotective film at the position being in contact with the plurality ofbumps, and the average thickness h3 of the first protective film at thecenter position between the plurality of bumps were measured by imageanalysis with the scanning electron microscope. Further, from these h1to h3, “the ratio (h3/h1) of the average thickness h3 of the firstprotective film at the center position between the plurality of bumps tothe average peak height h1 of the plurality of bumps” and “the ratio(h2/h1) of the average thickness h2 of the first protective film at theposition being in contact with the plurality of bumps to the averagepeak height h1 of the plurality of bumps” were calculated, and theresults are indicated in Table 2.

As indicated in the following Table 2, in Example 1, it was possible toconfirmed that after forming the first protective film by curing thecurable resin film, the ratio (h3/h1) of the average thickness h3 of thefirst protective film at the center position between the plurality ofbumps to the average peak height h1 of the plurality of bumps, and theratio (h2/h1) of the average thickness h2 of the first protective filmat the position being in contact with the plurality of bumps satisfiedthe relationship represented by the following expression{{(h2/h1)−(h3/h1)}≤0.1}. In Example 1, it was possible to confirm thatthe value calculated on the left side of the above expression was 0.06,and a flat-like first protective film in which the distortion issuppressed was formed.

Manufacture and Evaluation of First Protective Film Forming SheetExample 2 and Comparative Examples

A first protective film forming sheet of Example 2 was manufactured byusing the same method as that used in Example 1 except that thethickness of the first pressure-sensitive adhesive layer on the firstprotective film forming sheet was set to be 80 μm, and the thickness ofthe curable resin film was set to be 60 μm, and the evaluation wasperformed as described above. The results are indicated in Table 2.

Further, a first protective film forming sheet of Comparative Example 1was manufactured by using the same method as that used in Example 1except that the thickness of the first pressure-sensitive adhesive layeron the first protective film forming sheet was set to be 60 μm, and thethickness of the curable resin film was set to be 80 μm, and theevaluation was performed as described above. The results are indicatedin Table 2.

As indicated in the following Table 2, in Example 2, it was possible toconfirmed that after forming the first protective film by curing thecurable resin film, the ratio (h3/h1) of the average thickness h3 of thefirst protective film at the center position between the plurality ofbumps to the average peak height h1 of the plurality of bumps, and theratio (h2/h1) of the average thickness h2 of the first protective filmat the position being in contact with the plurality of bumps satisfiedthe relationship represented by the following expression{{(h2/h1)−(h3/h1)}≤0.1}. In addition, in Example 2, it was possible toconfirm that the value calculated on the left side of the aboveexpression was 0.09, and the first protective film on which a largedistortion in a concave shape was suppressed was formed.

In contrast, in comparative examples, the above-described (h3/h1) and(h2/h1) did not satisfy the next expression {{(h2/h1)−(h3/h1)}≤0.1}. Inthe comparative examples, it was possible to confirm that the valuecalculated on the left side of the above expression was 0.19, and alarge distortion in a concave shape occurred.

TABLE 1 Examples 1, 2, Comparative Example Contained component (ratio ofthe content Polymer component (A)-1 100 (parts by mass)) ofthermosetting resin Epoxy resin (B1)-1 135 composition (B1)-2 90 (B1)-3150 Thermal curing agent (B2)-1 180 Curing accelerator (C)-1 1 Filler(D)-1 160

TABLE 2 Examples Comparative 1 2 Example First protective film Curableresin film Thickness (μm) 40 60 80 forming sheet Weight-averagemolecular 340~1,000 340~1,000 340~1,000 weight of curable componentAverage particle diameter of 0.05 0.05 0.05 filler (D) (μm) Amount offiller (D) (% by mass) 19 19 19 First supporting sheet Thickness (μm)105 105 105 First pressure-sensitive adhesive Thickness (μm) 100 80 60layer Evaluation results Height h1 of bump (μm) 200 200 200 Averagethickness h2 of first protective film at position being 116 144 176 incontact with a plurality of bumps (μm) Average thickness h3 of firstprotective film at center 104 126 138 position between with a pluralityof bumps (μm) (h2/h1) − (h3/h1) 0.06 0.09 0.19

From the results of the above-described examples, as defined in thepresent invention, after optimizing the weight-average molecular weightof the curable component contained in the curable resin film used in forforming the first protective film, when a dimensional relationshipbetween of the first protective film cured under predeterminedconditions and the plurality of bumps on a semiconductor wafer havingthe plurality of bumps of a predetermined dimensional shape andarrangement condition are appropriately set, and thereby the occurrenceof the large distortion in the concave shape on the first protectivefilm disposed between the bumps can be suppressed. Therefore, it ispossible to improve the inspection accuracy and the dicing accuracy inthe manufacturing step and to manufacture a semiconductor packageexcellent in the reliability.

INDUSTRIAL APPLICABILITY

The present invention can be used for manufacturing a semiconductor chipor the like having a bump at a connection pad portion used in a flipchip mounting method.

REFERENCE SIGNS LIST

-   -   1,10 . . . CURABLE RESIN FILM    -   1 a . . . FIRST PROTECTIVE FILM    -   1A, 1B, 1C . . . FIRST PROTECTIVE FILM FORMING SHEET,    -   11, 11A, 11B . . . FIRST SUPPORTING SHEET    -   11 a . . . ONE SURFACE (FIRST SUPPORTING SHEET)    -   12 . . . FIRST BASE MATERIAL,    -   12 a . . . SURFACE (FIRST BASE MATERIAL)    -   13 . . . FIRST PRESSURE-SENSITIVE ADHESIVE LAYER,    -   13 a . . . SURFACE (FIRST PRESSURE-SENSITIVE ADHESIVE LAYER),    -   14 . . . FIRST INTERLAYER,    -   5 . . . SEMICONDUCTOR WAFER,    -   5 a . . . SURFACE (BUMP-FORMED SURFACE: CIRCUIT SURFACE),    -   5 b . . . BACK SURFACE    -   51 . . . BUMP,    -   51 a . . . SURFACE (SURFACE OF BUMP)

1. A curable resin film for forming a first protective film on a surfacehaving a plurality of bumps in a semiconductor wafer by being attachedto the surface and being cured, wherein the curable resin film containsan epoxy-based thermosetting component having a weight-average molecularweight of 200 to 4,000 as a curable component, and wherein the firstprotective film that protects the plurality of bumps is formed byattaching the curable resin film to a surface of the semiconductor waferhaving the plurality of bumps with an average peak height h1 of 50 to400 μm, an average diameter D of 60 to 500 μm in a plan view, and anaverage pitch P of 100 to 800 μm, heating the attached curable resinfilm at 100° C. to 200° C. for 0.5 to 3 hours, and curing the heatedcurable resin film, and when longitudinal sections of the firstprotective film and the semiconductor wafer having the plurality ofbumps are observed by a scanning electron microscope, a ratio (h3/h1) ofan average thickness h3 of the first protective film at a centerposition between the plurality of bumps to the average peak height h1 ofthe plurality of bumps, and a ratio (h2/h1) of an average thickness h2of the first protective film at a position being in contact with theplurality of bumps to the average peak height h1 satisfy a relationshiprepresented by the following Expression (1).{(h2/h1)−(h3/h1)}≤0.1  (1)
 2. A curable resin film for forming a firstprotective film on a surface having a plurality of bumps in asemiconductor wafer by being attached to the surface and being cured,wherein the curable resin film contains an energy ray-curable componenthaving a weight-average molecular weight of 200 to 4,000 as a curablecomponent, and wherein the first protective film that protects theplurality of bumps is formed by attaching the curable resin film to asurface of the semiconductor wafer having the plurality of bumps with anaverage peak height h1 of 50 to 400 μm, an average diameter D of 60 to500 μm in a plan view, and an average pitch P of 100 to 800 μm,irradiating the attached curable resin film with energy rays under acondition of illuminance of 50 to 500 mW/cm², and light intensity of 100to 2,000 mJ/cm², and curing the irradiated curable resin film, and whenlongitudinal sections of the first protective film and the semiconductorwafer having the plurality of bumps are observed by a scanning electronmicroscope, a ratio (h3/h1) of an average thickness h3 of the firstprotective film at a center position between the plurality of bumps tothe average peak height h1 of the plurality of bumps, and a ratio(h2/h1) of an average thickness h2 of the first protective film at aposition being in contact with the plurality of bumps to the averagepeak height h1 satisfy a relationship represented by the followingExpression (1).{(h2/h1)−(h3/h1)}≤0.1  (1)
 3. The curable resin film according to claim1 which contains 5% to 80% by mass of filler having an average particlediameter of 5 to 1,000 nm.
 4. A first protective film forming sheetcomprising the curable resin film according to claim 1 on one surface ofa first supporting sheet.